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Inclusive dijet photoproduction in ultraperipheral heavy-ion collisions at the CERN LHC in next-to-leading order QCD

Inclusive dijet photoproduction in ultraperipheral heavy-ion collisions at the CERN LHC in... Inclusive dijet photoproduction in ultraperipheral heavy-ion collisions at the LHC in next-to-leading order QCD 1, 2, 3 4 V. Guzey and M. Klasen Department of Physics, University of Jyva¨skyla¨, P.O. Box 35, 40014 University of Jyva¨skyla¨, Finland Helsinki Institute of Physics, P.O. Box 64, 00014 University of Helsinki, Finland National Research Center “Kurchatov Institute”, Petersburg Nuclear Physics Institute (PNPI), Gatchina, 188300, Russia Institut fu¨r Theoretische Physik, Westfa¨lische Wilhelms-Universita¨t Mu¨nster, Wilhelm-Klemm-Straße 9, 48149 Mu¨nster, Germany We compute the cross section of inclusive dijet photoproduction in ultraperipheral Pb-Pb colli- sions at the LHC using next-to-leading order perturbative QCD. We demonstrate that our theoretical calculations provide a good description of various kinematic distributions measured by the ATLAS collaboration. We find that the calculated dijet photoproduction cross section is sensitive to nuclear modifications of parton distribution functions (PDFs) at the level of 10 to 20%. Hence, this process can be used to reduce uncertainties in the determination of these nuclear PDFs, whose current mag- nitude is comparable to the size of the calculated nuclear modifications of the dijet photoproduction cross section. I. INTRODUCTION Ultraperipheral collisions (UPCs) of relativistic ions correspond to large impact parameters between the nuclei exceeding the sum of their radii, so that short-range strong interactions between the ions are suppressed and reactions proceed rather via the emission of quasi-real photons by the colliding ions. Thus, UPCs allow one to study photon- photon and photon-hadron (proton, nucleus) interactions at high energies [1]. During the last decade, UPCs have become an active field of research, driven by experimental results obtained at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC), for a recent experimental review see, e.g., [2]. Notable examples of various UPC processes and their analyses include the two-photon production of dilepton pairs [3, 4]; light-by- light scattering γγ → γγ and searches for potential physics beyond the Standard Model [5–7]; an electromagnetic double-scattering contribution to dimuon pair production in photon-photon scattering [8]; exclusive photoproduction of charmonia in proton-proton [9, 10], proton-nucleus [11] and nucleus-nucleus [12–15] UPCs and of bottomonia in proton-proton [16] and proton-nucleus UPCs [17]; new constraints on the small-x gluon distribution in the proton [18, 19] and heavy nuclei [20, 21] and the dynamics of strong interactions at high energies in the color dipole framework [22–24]; and exclusive photoproduction of ρ mesons on nuclei [25–28] as well as tests of models of nuclear shadowing [29, 30]. Focusing on UPC studies of nuclear structure in QCD at the LHC, coherent J/ψ photoproduction in Pb-Pb UPCs at s = 2.76 TeV [12–15] revealed a significant nuclear suppression of the measured rapidity distributions. In NN the framework of the leading logarithmic approximation of perturbative QCD [31], it can be interpreted as evidence 2 2 −3 2 2 of large nuclear gluon shadowing, R = f (x, µ )/[Af (x, µ )] ≈ 0.6 at x = 10 and µ = 3 GeV (f g/A g/N g/A and f are gluon densities in Pb and the proton, respectively). This value of R agrees with predictions of g/N g the leading twist nuclear shadowing model [32], which are characterized by small theoretical uncertainties in this kinematic region. It is also broadly consistent with the EPS09 [33], nCTEQ15 [34], and EPPS16 [35] nuclear parton distribution functions (nPDFs), which however have significant uncertainties in this kinematic regime. Note that in the collinear factorization framework, next-to-leading order (NLO) perturbative QCD corrections to the cross section of J/ψ photoproduction are large [36, 37] and the relation between the gluon parton distribution function (PDF) and the gluon generalized parton distribution (GPD) is model-dependent, which makes it challenging to interpret the UPC data on J/ψ photoproduction on nuclei in terms of the NLO gluon nPDF. The program of UPC measurements continues with Run 2 at the LHC, where besides photoproduction of vector mesons, inclusive dijet photoproduction in Pb-Pb UPCs AA → A + 2jets + X has also recently been measured by the ATLAS collaboration [38] (for leading-order QCD predictions for rates of this process, see [39]). The cross section of this process is sensitive to quark and gluon nPDFs f (x, µ ) in a wide range of the momentum fraction x and j/A the resolution scale µ > O(20) GeV, where one still expects sizable nuclear modifications of the PDFs. In addition, imposing the requirement that the target nucleus stays intact, one can study diffractive dijet photoproduction in UPCs AA → A + 2jets + X + A. Studies of this process may shed some light on the mechanism of QCD factorization breaking in diffractive photoproduction and, for the first time, give access to nuclear diffractive PDFs [40, 41]. While further progress in constraining nPDFs will benefit from studies of high-energy hard processes with nuclei in proton- arXiv:1811.10236v2 [hep-ph] 5 Jul 2019 2 A γ Remnant Jet Jet Jet Jet (a) (b) FIG. 1: Typical leading-order Feynman graphs for dijet photoproduction in UPCs of hadrons A and B. Graphs (a) and (b) correspond to the direct and resolved photon contributions, respectively. nucleus (pA) scattering at the LHC [42] and lepton-nucleus (eA) scattering at a future Electron-Ion Collider (EIC) [43] and LHeC [44], UPCs at the LHC present an important and complimentary method of obtaining new constraints on nPDFs in a wide kinematic range already now. In this work, we make predictions for the cross section of inclusive dijet photoproduction in Pb-Pb UPCs at the LHC using NLO perturbative QCD [45] and nCTEQ15 nPDFs. We show that our approach provides a good description of various cross section distributions measured by the ATLAS collaboration [38]. Our analysis also shows that the dijet photoproduction cross section in the considered kinematics is sensitive to nuclear modifications of the PDFs. As a function of the momentum fraction x , the ratio of the cross sections calculated with nPDFs and in the impulse approximation behaves similarly to R for a given µ and deviates from unity by 10 − 20% for the central nCTEQ15 fit. The calculations using EPPS16 nPDFs and predictions of the leading twist nuclear shadowing model give similar results. This suggests that inclusive dijet photoproduction on nuclei can be used to reduce uncertainties in the determination of nPDFs, which are currently significant and comparable in size to the magnitude of the calculated nuclear modifications of the dijet photoproduction cross section. The remainder of this paper is structured as follows. In Sec. II, we outline the formalism of dijet photoproduction in UPCs using NLO perturbative QCD. We present and discuss our results for the LHC in Sec. III and draw conclusions in Sec. IV. II. PHOTOPRODUCTION OF DIJETS IN UPCS IN NLO PERTURBATIVE QCD Typical leading-order (LO) Feynman diagrams for dijet photoproduction in UPCs of nuclei A and B are shown in Fig. 1, where the graphs (a) and (b) correspond to the direct and resolved photon contributions, respectively. Note that beyond LO, the separation of the direct and resolved photon contributions depends on the factorization scheme and scale (see the discussion below). Using the Weizs¨acker-Williams method, which allows one to treat the electromagnetic field of an ultra-relativistic ion as a flux of equivalent quasi-real photons [1, 46], and the collinear factorization framework for photon-nucleus scattering, the cross section of the UPC process AB → A + 2jets + X is given by [45] dσ(AB → A + 2jets + X) = Z Z Z y 1 x X max A,max 2 2 dy dx dx f (y)f (x , µ )f (x , µ )dσˆ(ab → jets) , (1) γ A γ A γ/A a/γ b/B y 0 x min A,min a,b where a, b are parton flavors; f (y) is the flux of equivalent photons emitted by ion A, which depends on the γ/A photon light-cone momentum fraction y; f (x , µ ) is the PDF of the photon, which depends on the momentum a/γ γ fraction x and the factorization scale µ ; f (x , µ ) is the nuclear PDF with x being the corresponding parton γ A A b/B momentum fraction; and dσˆ(ab → jets) is the elementary cross section for production of two- and three-parton final states emerging as jets in hard scattering of partons a and b. The sum over a involves quarks and gluons for the resolved photon contribution and the photon for the direct photon contribution dominating at x ≈ 1. At LO, the γ 3 direct photon contribution has support exactly only at x = 1, i. e., f = δ(1 − x ). At NLO, the virtual and γ a γ γ real corrections are calculated with massless quarks in dimensional regularization, ultraviolet (UV) divergences are renormalized in the MS scheme, infrared (IR) divergences are canceled and factorized into the proton and photon PDFs, respectively. For the latter, this implies a transformation from the DIS into the MS scheme. The integration limits are determined by the rapidities and transverse momenta of the produced jets, see Sec. III. Note that Eq. (1) is based on the clear separation of scales, which characterize the long-distance electromagnetic interaction and the short-distance strong interaction. It generalizes the NLO perturbative QCD formalism of collinear factorization for jet photoproduction in lepton-proton scattering developed in Refs. [45, 47–49], which successfully described HERA ep data on dijet photoproduction [50]. Hence, Eq. (1) involves universal nuclear PDFs f (x , µ ), which can be b/B A accessed in a variety of hard processes involving nuclear targets [33–35], and the universal photon PDFs f (x , µ ), a/γ + − which are determined by e e data, for a review, see [45]. Hence, the interplay between the direct and resolved photon contributions in Eq. (1) is also universal and controlled by the standard µ evolution equations of photon PDFs and the choice of the factorization scheme. In our analysis, we used the following input for Eq. (1). For photon PDFs f (x , µ ), we used the GRV HO a/γ parametrization [51], which we transformed from the DIS to the MS factorization scheme. These photon PDFs have been tested profoundly at HERA and the Large Electron-Positron (LEP) collider at CERN and are very robust, in particular at high x (dominated by the pQCD photon-quark splitting), which is correlated with the low-x gluons γ A and sea quarks in Pb that present one of the points of interest of the present study. For nuclear PDFs f (x , µ ), b/B A we employed the nCTEQ15 parametrization [34]. The photon flux f (y) produced by a relativistic point-like charge γ/A Z is given by the standard expression 2 2 2α Z 1 ζ e.m. 2 2 f (y) = ζK (ζ)K (ζ) − (K (ζ) − K (ζ)) , (2) γ/A 0 1 1 0 π y 2 where α is the fine-structure constant; K are modified Bessel functions of the second kind; ζ = ym b with m e.m. 0,1 p min p being the proton mass and b the minimal distance between two nuclei. For Pb-Pb UPCs, Eq. (2) with b = 14.2 min min fm reproduces very well the photon flux calculated taking into account the nuclear form factor and the suppression of strong interactions at impact parameters b < b , see the discussion in [52]. min The NLO calculation of the dijet photoproduction cross section using Eq. (1) is numerically implemented in an NLO parton-level Monte Carlo [45, 47–49], which has been successfully tested in many different environments (HERA, LEP, Tevatron). It implements the anti-k algorithm (but we have at most two partons in the jet) and all the kinematic conditions and cuts used in the ATLAS analysis [38] that are explicitly explained in the following section. Hadronization corrections and underlying event (UE) subtractions are not part of our analysis, but they are expected to be performed with PYTHIA simulations by the experiment once the data are final (as has been done at HERA). III. PREDICTIONS FOR DIJET PHOTOPRODUCTION IN PB-PB COLLISIONS AT THE LHC The main goal of the present paper is the first NLO QCD calculation of the cross section of inclusive dijet photo- production in Pb-Pb UPCs and the conclusion whether it can describe the results of the ATLAS measurement [38]. The ATLAS analysis was performed using the following conditions and selection criteria: • the anti-k algorithm with the jet radius R = 0.4; • the leading jet has p > 20 GeV, while the other jets have a different cut on p > 15 GeV as required [53], T,1 T,i6=1 which corresponds to 35 < H < 400 GeV, where H = p ; T T T,i • all jets have rapidities |η | < 4.4; • the combined mass of all reconstructed jets is 35 < m < 400 GeV; jets −4 • the parton momentum fraction on the photon side z = yx , 10 < z < 0.05; γ γ γ −4 • the parton momentum fraction on the nucleus side x , 5 × 10 < x < 1. A A The ATLAS results are presented as distributions in terms of the total jet transverse momentum H = p and T T,i the photon z and nucleus x light-cone momentum fractions γ A m m jets jets y −y jets jets z = √ e , x = √ e , (3) γ A s s NN NN 4 Pb-Pb, 5.02 TeV 0.0023 < x <0.0049 -2 0.0049 < x < 0.01 (×10 ) nCTEQ15 10 -4 0.01 < x < 0.022 (×10 ) -6 0.022 < x < 0.048 (×10 ) -8 0.048 < x < 0.1 (×10 ) -10 0.1 < x < 0.22 (×10 ) -12 0.22 < x < 0.47 (×10 ) ATLAS (prel., not unfold.) -2 -4 -6 -8 -10 -12 -14 -16 50 100 150 200 250 300 H (GeV) FIG. 2: NLO QCD predictions for the cross section of dijet photoproduction in Pb-Pb UPCs at s = 5.02 TeV in the NN ATLAS kinematics as a function of H for different bins of x . The central values and the corresponding shaded uncertainty T A bands are obtained using nCTEQ15 nPDFs. The crosses are the ATLAS data points that we extracted from [38]. where   1/2 2 2 P X X 1 E + p i z,i   m = E − ~p , y = ln . (4) jets i i jets 2 E − p i z,i i i In Eqs. (4), the index i runs over all measured jets; E and ~p denote the jet energy and momentum, respectively. i i Note that at LO, the kinematics of 2 → 2 parton scattering and the momentum fractions z and x can be exactly γ A reconstructed from the dijet measurement. At NLO, Eqs. (3) serve as hadron-level estimators of the momentum fractions entering Eq. (1); for brevity, we use the same notations in Eqs. (1) and (4). Figures 2, 3, 4, and 5 show our results for the cross section of dijet photoproduction in Pb-Pb UPCs in the ATLAS kinematics (see above) as a function of H , x , and z for different bins of these variables. They correspond to Figs. T A γ 12-15 of Ref. [38]. In each bin, our predictions are obtained using the central fit of nCTEQ15 nPDFs [34]. The shaded bands quantify the uncertainty of our results Δσ due to the uncertainty of nCTEQ15 nPDFs. It is calculated by dσ/dH dx (μb/GeV) T A 5 Pb-Pb, 5.02 TeV nCTEQ15 -2 -4 -6 -8 42 < H < 50 GeV -1 50 < H < 59 GeV (×10 ) -2 59 < H < 70 GeV (×10 ) -3 70 < H < 84 GeV (×10 ) -4 84 < H < 100 GeV (×10 ) -5 -10 100 < H < 119 GeV (×10 ) 10 T -6 119 < H < 141 GeV (×10 ) -7 141 < H < 168 GeV (×10 ) -8 168 < H < 200 GeV (×10 ) ATLAS (prel.,not unfol.) -12 -3 -2 -1 0 10 10 10 10 FIG. 3: NLO QCD predictions for the cross section of dijet photoproduction in Pb-Pb UPCs at s = 5.02 TeV in the NN ATLAS kinematics as a function of x for different bins of H . The crosses are the ATLAS data points that we extracted from A T [38]. adding in quadrature the individual uncertainties corresponding to each of 32 error sets Δσ = (σ(f ) − σ(f )) , (5) k k+1 k=1, odd where σ(f ) is the cross section calculated using the f nCTEQ15 error nPDFs. k k A comparison of our results shown in Figs. 2, 3, 4, and 5 with Figs. 12-15 of Ref. [38] demonstrates that our calculations describe well the corresponding distributions. To illustrate this point, in Figs. 2 and 3, which present the phenomenologically important distributions in H and x , respectively, we also explicitly show by crosses the T A ATLAS data points, which we extracted from [38] using the WebPlotDigitizer tool [54]. One can readily see from these figures that the results of our calculations describe both the shape and normalization of the data rather well. The description of the remaining two distributions is also adequate. Note that the ATLAS data is preliminary and has not been corrected (unfolded) for the detector response. dσ/dH dx (μb/GeV) T A 6 Pb-Pb, 5.02 TeV nCTEQ15 -1 -2 -3 -4 -5 -6 42 < H < 50 GeV -7 -1 50 < H < 59 GeV (×10 ) -2 59 < H < 70 GeV (×10 ) -3 70 < H < 84 GeV (×10 ) -8 10 -4 84 < H < 100 GeV (×10 ) -5 100 < H < 119 GeV (×10 ) -6 -9 119 < H < 141 GeV (×10 ) 10 T -7 141 < H < 168 GeV (×10 ) -8 168 < H < 200 GeV (×10 ) -10 -4 -3 -2 -1 10 10 10 10 FIG. 4: NLO QCD predictions for the cross section of dijet photoproduction in Pb-Pb UPCs at s = 5.02 TeV in the NN ATLAS kinematics as a function of z for different bins of H . γ T To assess the impact of measurements of the inclusive dijet photoproduction cross section on nPDFs, we focus on the x distribution. Our results are shown in Figs. 6 and 7. In Fig. 6, we show the ratio of the cross section calculated using nCTEQ15 nPDFs in lead to the one calculated in the impulse approximation (IA), where nuclear PDFs are assumed not to include any nuclear modifications and are given by the weighted sum of free proton and IA neutron PDFs, f = Zf + (A − Z)f . The panels in this figure corresponds to nine bins in H presented in b/p b/n b/A Fig. 3 (the numerator of the presented ratio is given by the curves in Fig. 3). One can see that the cross section 2 2 ratio as a function of x behaves similarly to the ratio R = f (x, µ )/[Af (x, µ )] of the nuclear and nucleon A g g/A g/N gluon distributions. It dips below unity for x < 0.01 due to nuclear shadowing and then becomes enhanced around x = 0.1 due to the assumed gluon antishadowing. For x > 0.3, the cross section ratio shows again a suppression A A due to the EMC effect encoded in the nPDFs. While the scaling violations (the H dependence) of the shown ratios are difficult to see, they seem to be positive at small x ∼ 0.01 and negative at large x, as they should be, cf. [34, 35]. Note that in spite of large values of the resolution scale probed in the considered kinematics, µ > O(20) GeV, one can see that one is still sensitive to nuclear modifications of the PDFs at the 10 − 20% level for the central value of our predictions. One should also note that the uncertainty due to nPDFs, which is given by the shaded bands, is dσ/dH dz (μb/GeV) T γ 7 0.0002 < z < 0.0003 Pb-Pb, 5.02 TeV -2 0.0003 < z < 0.0006 (×10 ) -4 nCTEQ15 0.0006 < z < 0.0012 (×10 ) -6 0.0012 < z < 0.0022 (×10 ) -8 0.0022 < z < 0.0042 (×10 ) 10 -10 0.0042 < z < 0.0077 (×10 ) -12 0.0077 < z < 0.0144 (×10 ) -14 0.0144 < z < 0.0269 (×10 ) -2 -4 -6 -8 -10 -12 -14 -16 -3 -2 -1 0 10 10 10 10 FIG. 5: NLO QCD predictions for the cross section of dijet photoproduction in Pb-Pb UPCs at s = 5.02 TeV in the NN ATLAS kinematics as a function of x for different bins of z . A γ significant and comparable to the size of the discussed nuclear modifications. This can be viewed as an opportunity to reduce uncertainties of nPDFs using data on cross section of inclusive dijet photoproduction in nuclei in global QCD fits of nPDFs. In Fig. 7, we show our predictions for the dijet cross section as a function of x integrated over H and z . The A T γ top panel presents separately the resolved (green, dot-dashed) and the direct (blue, dashed) photon contributions to the cross section as well as their sum (red, solid). As can be expected, because of the correlation between x and z , see Eq. (3), the resolved photon contribution dominates for x > 0.01. We find that for small x < 0.01, γ A A the two contributions are comparable with the direct contribution being somewhat larger. While this behavior is qualitatively similar to the results of the LO analysis in the framework of PYTHIA 8 with EPPS16 nPDFs [55], the relative contribution of the resolved photon term is larger at NLO, but this statement depends of course on the choice of the photon factorization scheme and scale. The middle panel of Fig. 7 presents the ratio to the impulse approximation. Similarly to the trend already observed in Fig. 6 and discussed above, this ratio as a function of x behaves similarly to R . This behavior is similar to the A g one observed in the case of dijet photoproduction in the kinematics of an Electron-Ion Collider (EIC) [56]. dσ/dz dx (μb) γ A 8 1.3 1.3 42 < H < 50 GeV T 100 < H < 119 GeV 1.2 1.2 1.1 1.1 1.0 1.0 0.9 0.9 0.8 0.8 0.7 0.7 0.6 0.6 1.3 1.3 50 < H < 59 GeV 119 < H < 141 GeV 1.2 1.2 T T 1.1 1.1 1.0 1.0 0.9 0.9 0.8 0.8 0.7 0.7 0.6 0.6 1.3 1.3 59 < H < 70 GeV 141 < H < 168 GeV 1.2 1.2 T T 1.1 1.1 1.0 1.0 0.9 0.9 0.8 0.8 0.7 0.7 0.6 0.6 1.3 1.3 168 < H < 200 GeV 70 < H < 84 GeV 1.2 1.2 T 1.1 1.1 1.0 0.9 1.0 0.8 0.9 0.7 0.6 0.8 -3 -2 -1 0 10 10 10 10 0.7 0.6 1.3 84 < H < 100 GeV 1.2 1.1 1.0 0.9 0.8 0.7 0.6 -3 -2 -1 0 10 10 10 10 FIG. 6: NLO QCD predictions for the ratio of the cross section of dijet photoproduction to that calculated in IA in Pb-Pb UPCs at s = 5.02 TeV in the ATLAS kinematics as a function of x for different H bins. The shaded bands give the NN A T uncertainty of nCTEQ15 nPDFs. Note that in the future and if/when experimental data become available, to study nuclear modifications of nPDFs one can directly form the ratio of dijet cross sections measured in Pb-Pb and proton-proton (pp) UPCs as a function of x . While the systematics are highly correlated between bins in x , the information on nPDFs is in the shape of A A the cross section ratio, see the middle panel of Fig. 7 and its discussion above. Also, while the central Pb-Pb and pp collisions are very different, Pb-Pb and pp UPCs have comparable multiplicities. Thus, one can expect that the systematic uncertainties largely cancel in the nucleus-to-proton cross section ratio. Finally, the bottom panel of Fig. 7 presents the ratio of the dijet cross section calculated using nCTEQ15 nPDFs to the one calculated with the central value of EPPS16 nPDFs. The shaded band quantifies the uncertainty of the nCTEQ15 fit. One can see from the panel that the two parameterizations of nPDFs give similar predictions, which differ by at most 5% for all but one values of x . We have also explicitly checked that the use of nPDFs calculated in the model of leading twist nuclear shadowing [32] gives similarly close predictions for the dijet photoproduction cross section. In our calculations, following the standard prescription for setting the hard scale in QCD calculations, we used nCTEQ15/nCTEQ15(IA)nCTEQ15/nCTEQ15(IA) nCTEQ15/nCTEQ15(IA) nCTEQ15/nCTEQ15(IA) nCTEQ15/nCTEQ15(IA) 9 Pb-Pb, 5.02 TeV nCTEQ15 resolved direct -3 -2 -1 0 10 10 10 10 1.3 1.2 1.1 1.0 0.9 0.8 0.7 0.6 -3 -2 -1 0 10 10 10 10 1.3 1.2 1.1 1.0 0.9 0.8 0.7 0.6 -3 -2 -1 0 10 10 10 10 FIG. 7: NLO QCD predictions for the cross section of dijet photoproduction in Pb-Pb UPCs at s = 5.02 TeV in the NN ATLAS kinematics as a function of xA. Top: The resolved (green, dot-dashed) and direct (blue, dashed) photon contributions and their sum (red, solid). Middle: The ratio to the impulse approximation. Bottom: The ratio of cross sections calculated using the nCTEQ15 and EPPS16 nPDFs. The shaded bands show the uncertainty of nCTEQ15 nPDFs. µ = 2E in Eq. (1). In detail, we performed calculations using µ = (E /4, E /2, E , 2 E , 4 E ) both at T,1 T,1 T,1 T,1 T,1 T,1 NLO and LO and found that (i) the integrated cross section of inclusive dijet photoproduction at NLO as a function of µ is approximately constant is the vicinity of µ = 2E , (ii) while the NLO cross section slightly increases with T,1 an increase of µ up to 2E and then starts to decrease again, the LO cross section steeply decreases monotonically, T,1 and (iii) the values of the two cross sections are close around µ = 2E . Therefore, µ = 2E in Eq. (1) corresponds T,1 T,1 to the choice, which is most numerically stable against higher-order corrections. In this work, we used the framework of collinear factorization and NLO perturbative QCD to examine the sensitivity of the dijet photoproduction cross section to nuclear modifications of PDFs. Alternatively, one can use this process to look for signs of the BFKL and gluon saturation dynamics in the high-energy (k ) factorization approach [57]. dσ/dx (nb) nCTEQ15/EPPS16 nCTEQ15/nCTEQ15(IA) A 10 IV. CONCLUSIONS In this work, we calculated the cross section of inclusive dijet photoproduction in Pb-Pb UPCs at the LHC using NLO perturbative QCD and nCTEQ15 nPDFs. We showed that our approach provides a good description of various cross section distributions measured by the ATLAS collaboration. We found that the calculated dijet photoproduction cross section is sensitive to nuclear modifications of the PDFs. In particular, as a function of the nucleus momentum fraction x , the ratio of the cross sections calculated with nPDFs and in the impulse approximation behaves similarly to R for given µ and deviates from unity by 10 − 20% for the central nCTEQ15 fit. The calculations using EPPS16 nPDFs and predictions of the leading twist nuclear shadowing model give similar results. Therefore, inclusive dijet photoproduction on nuclei has the potential to reduce uncertainties in determination of nPDFs, which are comparable to the magnitude of the calculated nuclear modifications of the dijet photoproduction cross section. Our present analysis is a step in this direction. Acknowledgments VG would like to thank A. Angerami, I. Helenius, K. Kovarik, H. Paukkunen, and M. Strikman for useful discussions and the Institut fu¨r Theoretische Physik, Westfa¨lische Wilhelms-Universit¨at Mu¨nster for hospitality. VG’s research is supported in part by RFBR, research project 17-52-12070. The authors gratefully acknowledge financial support of DFG through the grant KL 1266/9-1 within the framework of the joint German-Russian project “New constraints on nuclear parton distribution functions at small x from dijet production in γA collisions at the LHC”. [1] A. J. Baltz et al., Phys. Rept. 458, 1 (2008) [arXiv:0706.3356 [nucl-ex]]. [2] S. R. Klein, Nucl. Phys. A 967, 249 (2017) [arXiv:1704.04715 [nucl-ex]]. [3] S. R. Klein, Phys. Rev. C 97, 054903 (2018) [arXiv:1801.04320 [nucl-th]]. [4] V. P. Gonc ¸alves, M. M. Jaime, D. E. Martins and M. S. Rangel, Phys. Rev. D 97, 074024 (2018) [arXiv:1802.07339 [hep-ph]]. [5] D. d’Enterria and G. G. da Silveira, Phys. Rev. Lett. 111, 080405 (2013) [Erratum: Phys. Rev. Lett. 116, 129901 (2016)] [arXiv:1305.7142 [hep-ph]]. [6] S. Fichet, G. von Gersdorff, B. Lenzi, C. Royon and M. Saimpert, JHEP 1502, 165 (2015) [arXiv:1411.6629 [hep-ph]]. [7] M. K lusek-Gawenda, P. Lebiedowicz and A. Szczurek, Phys. Rev. C 93, 044907 (2016) [arXiv:1601.07001 [nucl-th]]. [8] A. van Hameren, M. K lusek-Gawenda and A. Szczurek, Phys. Lett. B 776, 84 (2018) [arXiv:1708.07742 [hep-ph]]. [9] R. Aaij et al. [LHCb Collaboration], J. Phys. G 40, 045001 (2013) [arXiv:1301.7084 [hep-ex]]. [10] R. Aaij et al. [LHCb Collaboration], J. Phys. G 41, 055002 (2014) [arXiv:1401.3288 [hep-ex]]. [11] B. B. Abelev et al. [ALICE Collaboration], Phys. Rev. Lett. 113, 232504 (2014) [arXiv:1406.7819 [nucl-ex]]. [12] E. Abbas et al. [ALICE Collaboration], Eur. Phys. J. C 73, 2617 (2013) [arXiv:1305.1467 [nucl-ex]]. [13] B. Abelev et al. [ALICE Collaboration], Phys. Lett. B 718, 1273 (2013) [arXiv:1209.3715 [nucl-ex]]. [14] J. Adam et al. [ALICE Collaboration], Phys. Lett. B 751, 358 (2015) [arXiv:1508.05076 [nucl-ex]]. [15] V. Khachatryan et al. [CMS Collaboration], Phys. Lett. B 772, 489 (2017) [arXiv:1605.06966 [nucl-ex]]. [16] R. Aaij et al. [LHCb Collaboration], JHEP 1509, 084 (2015) [arXiv:1505.08139 [hep-ex]]. [17] R. Chudasama et al. [CMS Collaboration], PoS ICPAQGP 2015, 042 (2017) [arXiv:1607.00786 [hep-ex]]. [18] S. P. Jones, A. D. Martin, M. G. Ryskin and T. Teubner, JHEP 1311, 085 (2013) [arXiv:1307.7099 [hep-ph]]. [19] V. Guzey and M. Zhalov, JHEP 1310, 207 (2013) [arXiv:1307.4526 [hep-ph]]. [20] A. Adeluyi and C. A. Bertulani, Phys. Rev. C 85, 044904 (2012) [arXiv:1201.0146 [nucl-th]]. [21] V. Guzey, E. Kryshen, M. Strikman and M. Zhalov, Phys. Lett. B 726, 290 (2013) [arXiv:1305.1724 [hep-ph]]. [22] T. Lappi and H. M¨ antysaari, Phys. Rev. C 87, 032201 (2013) [arXiv:1301.4095 [hep-ph]]. [23] V. P. Goncalves, B. D. Moreira and F. S. Navarra, Phys. Rev. C 90, 015203 (2014) [arXiv:1405.6977 [hep-ph]]. [24] H. M¨ antysaari and B. Schenke, Phys. Lett. B 772, 832 (2017) [arXiv:1703.09256 [hep-ph]]. [25] C. Adler et al. [STAR Collaboration], Phys. Rev. Lett. 89, 272302 (2002) [nucl-ex/0206004]. [26] B. I. Abelev et al. [STAR Collaboration], Phys. Rev. C 77, 034910 (2008) [arXiv:0712.3320 [nucl-ex]]. [27] G. Agakishiev et al. [STAR Collaboration], Phys. Rev. C 85, 014910 (2012) [arXiv:1107.4630 [nucl-ex]]. [28] J. Adam et al. [ALICE Collaboration], JHEP 1509, 095 (2015) [arXiv:1503.09177 [nucl-ex]]. [29] V. Rebyakova, M. Strikman and M. Zhalov, Phys. Lett. B 710, 647 (2012) [arXiv:1109.0737 [hep-ph]]. [30] L. Frankfurt, V. Guzey, M. Strikman and M. Zhalov, Phys. Lett. B 752, 51 (2016) [arXiv:1506.07150 [hep-ph]]. [31] M. G. Ryskin, Z. Phys. C 57, 89 (1993). [32] L. Frankfurt, V. Guzey and M. Strikman, Phys. Rept. 512, 255 (2012) [arXiv:1106.2091 [hep-ph]]. [33] K. J. Eskola, H. Paukkunen and C. A. Salgado, JHEP 0904, 065 (2009) [arXiv:0902.4154 [hep-ph]]. [34] K. Kovarik et al., Phys. Rev. D 93, 085037 (2016) [arXiv:1509.00792 [hep-ph]]. 11 [35] K. J. Eskola, P. Paakkinen, H. Paukkunen and C. A. Salgado, Eur. Phys. J. C 77, 163 (2017) [arXiv:1612.05741 [hep-ph]]. [36] D. Y. Ivanov, A. Sch¨ afer, L. Szymanowski and G. Krasnikov, Eur. Phys. J. C 34, 297 (2004) [Erratum: Eur. Phys. J. C 75, 75 (2015)] [hep-ph/0401131]. [37] S. P. Jones, A. D. Martin, M. G. Ryskin and T. Teubner, J. Phys. G 43, 035002 (2016) [arXiv:1507.06942 [hep-ph]]. [38] The ATLAS collaboration, ”Photo-nuclear dijet production in ultra-peripheral Pb+Pb collisions”, ATLAS-CONF-2017- 011, February 2017. [39] M. Strikman, R. Vogt and S. N. White, Phys. Rev. Lett. 96, 082001 (2006) [hep-ph/0508296]. [40] V. Guzey and M. Klasen, JHEP 1604, 158 (2016) [arXiv:1603.06055 [hep-ph]]. [41] E. Basso, V. P. Goncalves, A. K. Kohara and M. S. Rangel, Eur. Phys. J. C 77, no.9, 600 (2017) [arXiv:1705.08834 [hep-ph]]. [42] C. A. Salgado et al., J. Phys. G 39, 015010 (2012) [arXiv:1105.3919 [hep-ph]]. [43] A. Accardi et al., Eur. Phys. J. A 52, 268 (2016) [arXiv:1212.1701 [nucl-ex]]. [44] J. L. Abelleira Fernandez et al. [LHeC Study Group], J. Phys. G 39, 075001 (2012) [arXiv:1206.2913 [physics.acc-ph]]. [45] M. Klasen, Rev. Mod. Phys. 74, 1221 (2002) [hep-ph/0206169]. [46] C. A. Bertulani, S. R. Klein and J. Nystrand, Ann. Rev. Nucl. Part. Sci. 55, 271 (2005) [nucl-ex/0502005]. [47] M. Klasen and G. Kramer, Z. Phys. C 72, 107 (1996) [hep-ph/9511405]. [48] M. Klasen and G. Kramer, Z. Phys. C 76, 67 (1997) [hep-ph/9611450]. [49] M. Klasen, T. Kleinwort and G. Kramer, Eur. Phys. J. direct 1, 1 (1998) [hep-ph/9712256]. [50] M. Klasen and G. Kramer, Eur. Phys. J. C 71, 1774 (2011) [arXiv:1104.0095 [hep-ph]]. [51] M. Glu ¨ck, E. Reya and A. Vogt, Phys. Rev. D 46, 1973 (1992). [52] J. Nystrand, Nucl. Phys. A 752, 470 (2005) [hep-ph/0412096]. [53] M. Klasen and G. Kramer, Phys. Lett. B 366, 385 (1996) [hep-ph/9508337]. [54] http://arohatgi.info/WebPlotDigitizer [55] I. Helenius, arXiv:1806.07326 [hep-ph]. [56] M. Klasen and K. Kovarik, Phys. Rev. D 97, no.11, 114013 (2018) [arXiv:1803.10985 [hep-ph]]. [57] P. Kotko, K. Kutak, S. Sapeta, A. M. Stasto and M. Strikman, Eur. Phys. J. C 77, no.5, 353 (2017 [arXiv:1702.03063 [hep-ph]]. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png High Energy Physics - Phenomenology arXiv (Cornell University)

Inclusive dijet photoproduction in ultraperipheral heavy-ion collisions at the CERN LHC in next-to-leading order QCD

Guzey, V.; Klasen, M.
High Energy Physics - Phenomenology , Volume 2018 (1811) – Nov 26, 2018
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References (63)

  • P. Abreu, T. Adye, I. Ajinenk, G. Alekseev, R. Alemany, P. Allport, S. Almehed, U. Amaldi, S. Amato, P. Andersson, A. Andreazza, P. Antilogus, W-D. Ape, Y. Arnoud, P. Bambade, M. Barbi, D. Bardin, G. Barker, M. Bates, J. Baudot, K. Becks, M. Begalli, P. Beillière, Y. Belokopytov, K. Belous, A. Benvenut, C. Bérat, M. Berggren, F. Bianchi, M. Bigi, M. Bilenky, P. Billoir, M. Bizouard, D. Bloch, M. Blume, M. Bonesini, W. Bonivento, P. Boóth, A. Borgland, G. Borisov, O. Botner, E. Boudinov, B. Bouquet, C. Bourdarios, T. Bowcock, M. Bozzo, P. Branchini, T. Brenke, R. Brenner, R. Brown, P. Bruckman, J. Brunet, L. Bugge, T. Buran, T. Burgsmueller, P. Buschmann, S. Cabrera, M. Caccia, M. Calvi, A. Camacho, Rozas, T. Campores, V. Canale, M. Canepa, F. Carena, L. Carrol, C. Caso, F. Cavallo, V. Chabaud, M. Chapkin, L. Chaussard, P. Checchia, G. Chelkov, M. Chen, R. Chierici, P. Chliapnikov, V. Chorowicz, J. Chudoba, V. Cindro, P. Collins, M. Colomer, G. Cosme, J-H. Cowel, H. Crawley, D. Crennell, J. Cuevas, Maestro, S. Czellár, J. Dahm, B. Dalmagne, G. Damgaard, P. Dauncey, M. Davenpor, W. a, Silva, A. Deghorain, G. Ricca, P. Delpierre, N. Demaria, A. Angelis, W. Boer, S. Brabandere, C. Clercq, C. Vaissière, L. Paula, K. Doroba, M. Dracos, J. Drees, K. Drees, M. Dris, J. Durand, D. Edsall, R. Ehre, G. Eigen, T. Ekelof, G. Ekspong, M. Elsing, J. Engel, B. Eržen, M. to, Santo, E. Falk, G. Fanourakis, D. Fassouliotis, M. Feindt, A. Fenyuk, P. Ferrari, A. Ferrer, S. Fichet, T. ippas, H. Foeth, E. Fokitis, F. Fontanelli, F. Forment, B. Franek, A. Frodesen, J. Fuster, A. Galloni, D. Gamba, M. Gandelman, C. García, J. Garcìa, C. Gaspar, D. Gelé, J. Gerber, R. Gokieli, B. Golob, P. Gonçalves, G. Gopal, L. Gorn, M. Górski, Y. Gouz, E. Graziani, C. Green, A. th, P. Gris, G. Grosdidier, K. Grzelak, S. Gumenyuk, M. Gunther, J. Guy, F. Hahn, S. Hahn, Z. Hajduk, A. Hallgren, K. Hamacher, V. Hedberg, R. Henriques, J. Hernández, P. Herquet, H. Herr, T. Hessing, J. Heuser, E. Higón, S. Holmgren, P. Holt, D. Holthuizen, S. Hoorelbeke, M. Houlden, J. Hrubec, I. Kronkvist, J. Krst, Z. Krumstein, P. Kubinec, W. Kucewicz, K. Kurvinen, I. Laktineh, J. Lamsa, L. Lanceri, D. Lane, P. Langefeld, V. Lapin, J. Laugier, R. Lauhakangas, V. Lefebure, C. Legan, A. Leisos, R. Leitner, J. Lemonne, G. Lenzen, D. Liko, A. Lipniacka, I. Lippi, J. Loken, J. López, D. Loukas, L. Lyonsa, V. Malychev, F. Mand, J. Marco, R. Marco, B. Maréchal, J. Masik, F. Matorras, C. Matteuzzi, J. Medbø, C. Meroni, S. Meyer, W. Meyer, E. Migliore, T. Moa, K. Moenig, M. Monge, H. Mueller, L. Mundim, F. Naraghi, S. Navas, S. Nemecek, V. Nikolaenko, M. Nikolenko, P. Niss, A. Nomerotski, A. Normand, A. Nygren, A. OlshevskP, S. Ortuno, M. Paganonig, L. Pape, C. Parkes, F. Parodi, U. Parzefal, O. Podobr (2004)

    Search for charginos, neutralinos and gravitinos at LEP

  • (2008)

    034910 [arXiv:0712.3320 [nucl-ex]

  • H. Mantysaari, B. Schenke (2017)

    Probing subnucleon scale fluctuations in ultraperipheral heavy ion collisions

    Physics Letters B, 772

  • A. Accardi, A. Accardi, J. Albacete, M. Anselmino, N. Armesto, E. Aschenauer, A. Bacchetta, D. Boer, W. Brooks, T. Burton, N. Chang, W. Deng, W. Deng, A. Deshpande, M. Diehl, A. Dumitru, R. Dupré, R. Ent, S. Fazio, Haiyan Gao, V. Guzey, H. Hakobyan, Y. Hao, D. Hasch, R. Holt, T. Horn, M. Huang, A. Hutton, C. Hyde, J. Jalilian-Marian, S. Klein, B. Kopeliovich, Y. Kovchegov, K. Kumar, K. Kumerički, M. Lamont, T. Lappi, J. Lee, Y. Lee, E. Levin, E. Levin, F. Lin, V. Litvinenko, T. Ludlam, C. Marquet, Z. Meziani, R. Mckeown, A. Metz, R. Milner, V. Morozov, A. Mueller, B. Müller, B. Müller, D. Müller, P. Nadel-Turonski, H. Paukkunen, A. Prokudin, V. Ptitsyn, X. Qian, J. Qiu, M. Ramsey-Musolf, T. Roser, F. Sabatié, R. Sassot, G. Schnell, P. Schweitzer, E. Sichtermann, M. Stratmann, M. Strikman, M. Sullivan, S. Taneja, S. Taneja, T. Toll, D. Trbojevic, T. Ullrich, R. Venugopalan, S. Vigdor, W. Vogelsang, C. Weiss, B. Xiao, F. Yuan, Y. Zhang, L. Zheng, L. Zheng (2012)

    Electron-Ion Collider: The next QCD frontier

    The European Physical Journal A, 52

  • D. Ivanov, A. Schäfer, L. Szymanowski, G. Krasnikov (2015)

    Erratum to: Exclusive photoproduction of a heavy vector meson in QCD

    The European Physical Journal C, 75

  • Alice Collaboration (2012)

    Coherent J/psi photoproduction in ultra-peripheral Pb-Pb collisions at root s(NN)=2.76 TeV

    Physics Letters B, 718

  • V. Guzey, M. Klasen (2016)

    Diffractive dijet photoproduction in ultraperipheral collisions at the LHC in next-to-leading order QCD

    Journal of High Energy Physics, 2016

  • V. Anguelov, J. Anielski, T. Antičić, F. Antinori, P. Antonioli, L. Aphecetche, H. Appelshäuser, S. Arcelli, N. Armesto, R. Arnaldi, T. Aronsson, I. Arsene, M. Arslandok, A. Augustinus, R. Averbeck, M. Azmi, M. Bach, A. Badalà, Y. Baek, S. Bagnasco, R. Bailhache, R. Bala, A. Baldisseri, F. Pedrosa, R. Baral, A. Barbano, R. Barbera, F. Barile, G. Barnaföldi, L. Barnby, V. Barret, P. Bartalini, K. Barth, J. Bartke, E. Bartsch, M. Basile, N. Bastid, S. Basu, B. Bathen, G. Batigne, A. Camejo, B. Batyunya, P. Batzing, I. Bearden, H. Beck, C. Bedda, N. Behera, I. Belikov, F. Bellini, H. Martinez, R. Bellwied, R. Belmont, E. Belmont-Moreno, V. Belyaev, G. Bencédi, S. Beole, I. Berceanu, A. Bercuci, Y. Berdnikov, D. Berényi, R. Bertens, D. Berzano, L. Betev, A. Bhasin, I. Bhat, A. Bhati, B. Bhattacharjee, J. Bhom, L. Bianchi, N. Bianchi, C. Bianchin, J. Bielcik, J. Bielčíková, A. Bilandzic, R. Biswas, S. Biswas, S. Bjelogrlić, F. Blanco, D. Blau, C. Blume, F. Bock, A. Bogdanov, H. Boggild, L. Boldizsár, M. Bombara, J. Book, H. Borel, A. Borissov, M. Borri, F. Bossù, M. Botje, E. Botta, S. Böttger, P. Braun-Munzinger, M. Bregant, T. Breitner, T. Broker, T. Browning, M. Broz, E. Brucken, E. Bruna, G. Bruno, D. Budnikov, H. Buesching, S. Bufalino, P. Buncic, O. Busch, Z. Buthelezi, J. Buxton, D. Caffarri, X. Cai, H. Caines, L. Diaz, A. Caliva, E. Villar, P. Camerini, F. Carena, W. Carena, J. Castellanos, A. Castro, E. Casula, C. Cavicchioli, C. Sanchez, J. Čepila, P. Cerello, B. Chang, S. Chapeland, M. Chartier, J. Charvet, S. Chattopadhyay, V. Chelnokov, M. Cherney, C. Cheshkov, B. Cheynis, V. Barroso, D. Chinellato, P. Chochula, K. Choi, M. Chojnacki, S. Choudhury, P. Christakoglou, C. Christensen, P. Christiansen, T. Chujo, S. Chung, Z. Chunhui, C. Cicalò, L. Cifarelli, F. Cindolo, J. Cleymans, F. Colamaria, D. Colella, A. Collu, M. Colocci, G. Balbastre, Z. Valle, M. Connors, J. Contreras, T. Cormier, Y. Morales, I. Maldonado, P. Cortese, M. Cosentino, F. Costa, P. Crochet, R. Albino, E. Cuautle, L. Cunqueiro, T. Dahms, A. Dainese, A. Danu, D. Das, I. Das, Samir Das, A. Dash, S. Dash, S. De, A. Caro, G. Cataldo, J. Cuveland, A. Falco, D. Gruttola, N. Marco, S. Pasquale, A. Deisting, A. Deloff, E. Denes, G. D’erasmo, D. Bari, A. Mauro, P. Nezza, M. Corchero, T. Dietel, P. Dillenseger, R. Divià, Ø. Djuvsland, A. Dobrin, T. Dobrowolski, D. Gimenez, B. Dönigus, O. Dordic, A. Dubey, A. Dubla, L. Ducroux, P. Dupieux, R. Ehlers, D. Elia, H. Engel, B. Erazmus, F. Erhardt, D. Eschweiler, B. Espagnon, M. Estienne, S. Esumi, J. Eum, D. Evans, S. Evdokimov, G. Eyyubova, L. Fabbietti, D. Fabris, J. Faivre, A. Fantoni, M. Fasel, L. Feldkamp, D. Felea, A. Feliciello, G. Feofilov, J. Ferencei, A. Tellez, E. Ferreiro, A. Ferretti, A. Festanti, J. Figiel, M. Figueredo, S. Filchagin, D. Finogeev, F. Fionda, E. Fiore, M. Fleck, M. Floris, S. Foertsch, P. Foka, S. Fokin, E. Fragiacomo, A. Francescon, U. Frankenfeld, U. Fuchs, C. Furget, A. Furs, M. Girard, J. Gaardhøje, M. Gagliardi, A. Gago, M. Gallio, P. Ganoti, C. Gao, C. Garabatos, E. Garcia-Solis, C. Gargiulo, P. Gasik, M. Germain, A. Gheata, M. Gheata, P. Ghosh, S. Ghosh, P. Gianotti, P. Giubellino, P. Giubilato, E. Gladysz-dziadus, P. Glässel, A. Ramírez, P. GONZÁLEZ-ZAMORA, S. Gorbunov, L. Görlich, S. Gotovac, V. Grabski, L. Graczykowski, A. Grelli, A. Grigoras, C. Grigoras, V. Grigoriev, A. Grigoryan, S. Grigoryan, B. Grinyov, N. Grion, J. Grosse-Oetringhaus, J. Grossiord, R. Grosso, F. Guber, R. Guernane, B. Guerzoni, K. Gulbrandsen, H. Gulkanyan, T. Gunji, A. Gupta, R. Gupta, R. Haake, Ø. Haaland, C. Hadjidakis, M. Haiduc, H. Hamagaki, G. Hamar, L. Hanratty, A. Hansen, J. Harris, H. Hartmann, A. Harton, D. Hatzifotiadou, S. Hayashi, S. Heckel, M. Heide, H. Helstrup, A. Herghelegiu, G. Corral, B. Hess, K. Hetland, T. Hildén, H. Hillemanns, B. Hippolyte, P. Hristov, M. Huang, T. Humanic, N. Hussain, T. Hussain, D. Hutter, D. Hwang, R. Ilkaev, I. Ilkiv, M. Inaba, C. Ionita, M. Ippolitov, M. Irfan, M. Ivanov, V. Ivanov (2015)

    Coherent ψ( 2S ) photo-production in ultra-peripheral Pb–Pb collisions at

  • M. Klasen, G. Kramer (1995)

    Dijet Cross Sections at O($\alpha\alpha_s^2$) in Photon-Proton Collisions

    Physics Letters B

  • B. Abelev, E. al. (2007)

    ρ0 photoproduction in ultraperipheral relativistic heavy ion collisions at sNN=200 GeV

    Physical Review C, 77

  • S. Klein (2017)

    Ultra-peripheral collisions and hadronic structure

    Nuclear Physics, 967

  • V. Guzey, E. Kryshen, M. Strikman, M. Zhalov (2013)

    Evidence for nuclear gluon shadowing from the ALICE measurements of PbPb ultraperipheral exclusive J/ψ production

    Physics Letters B, 726

  • A. Baltz, G. Baur, D. d’Enterria, L. Frankfurt, F. Gelis, V. Guzey, K. Hencken, Y. Kharlov, M. Klasen, S. Klein, V. Nikulin, J. Nystrand, I. Pshenichnov, S. Sadovsky, E. Scapparone, J. Seger, M. Strikman, M. Tverskoy, R. Vogt, S. White, U. Wiedemann, P. Yepes, M. Zhalov (2007)

    The physics of ultraperipheral collisions at the LHC

    Physics Reports, 458

  • M. Klasen (2002)

    Theory of hard photoproduction

    Reviews of Modern Physics, 74

  • L. Aaij, B. Adeva, M. Adinolfi, A. Affolder, Z. Ajaltouni, J. Albrecht, Federico Alessio, M. Alexander, S. Ali, G. Alkhazov, P. Cartelle, A. Alves, S. Amato, S. Amerio, Y. Amhis, L. Anderlini, J. Anderson, R. Andreassen, M. Andreotti, J. Andrews, R. Appleby, O. Gutierrez, F. Archilli, A. Artamonov, M. Artuso, E. Aslanides, G. Auriemma, M. Baalouch, S. Bachmann, J. Back, A. Badalov, V. Balagura, W. Baldini, R. Barlow, C. Barschel, S. Barsuk, W. Barter, V. Batozskaya, T. Bauer, A. Bay, J. Beddow, F. Bedeschi, I. Bediaga, S. Belogurov, K. Belous, I. Belyaev, E. Ben-Haim, G. Bencivenni, S. Benson, J. Benton, A. Berezhnoy, R. Bernet, M. Bettler, M. Beuzekom, A. Bieñ, S. Bifani, T. Bird, A. Bizzeti, P. Bjørnstad, T. Blake, F. Blanc, J. Blouw, S. Blusk, V. Bocci, A. Bondar, N. Bondar, W. Bonivento, S. Borghi, A. Borgia, M. Borsato, T. Bowcock, E. Bowen, C. Bozzi, T. Brambach, J. Brand, J. Bressieux, D. Brett, M. Britsch, T. Britton, N. Brook, H. Brown, A. Bursche, G. Busetto, J. Buytaert, S. Cadeddu, R. Calabrese, O. Callot, M. Calvi, M. Gomez, A. Camboni, P. Campana, D. Perez, A. Carbone, G. Carboni, R. Cardinale, A. Cardini, H. Carranza-Mejia, L. Carson, K. Akiba, G. Casse, L. García, M. Cattaneo, C. Cauet, R. Cenci, M. Charles, P. Charpentier, S. Cheung, N. Chiapolini, M. Chrzaszcz, K. Ciba, X. Vidal, G. Ciezarek, P. Clarke, M. Clemencic, H. Cliff, J. Closier, C. Coca, V. Coco, J. Cogan, E. Cogneras, P. Collins, A. Comerma-Montells, A. Contu, A. Cook, M. Coombes, S. Coquereau, G. Corti, B. Couturier, G. Cowan, D. Craik, M. Torres, S. Cunliffe, R. Currie, C. D’Ambrosio, J. Dalseno, P. David, P. David, A. Davis, I. Bonis, K. Bruyn, S. Capua, M. Cian, J. Miranda, L. Paula, W. Silva, P. Simone, D. Decamp, M. Deckenhoff, L. Buono, N. D'el'eage, D. Derkach, O. Deschamps, F. Dettori, A. Canto, H. Dijkstra, S. Donleavy, F. Dordei, P. Dorosz, A. Su'arez, D. Dossett, A. Dovbnya, F. Dupertuis, P. Durante, R. Dzhelyadin, A. Dziurda, A. Dzyuba, S. Easo, U. Egede, V. Egorychev, S. Eidelman, D. Eijk, S. Eisenhardt, U. Eitschberger, R. Ekelhof, L. Eklund, I. Rifai, C. Elsasser, A. Falabella, C. Farber, C. Farinelli, S. Farry, D. Ferguson, V. Albor, F. Rodrigues, M. Ferro-Luzzi, S. Filippov, M. Fiore, M. Fiorini, C. Fitzpatrick, M. Fontana, F. Fontanelli, R. Forty, O. Francisco, M. Frank, C. Frei, M. Frosini, E. Furfaro, A. Torreira, D. Galli, M. Gandelman, P. Gandini, Y. Gao, J. Garofoli, P. Garosi, J. Tico, L. Garrido, C. Gaspar, R. Gauld, E. Gersabeck, M. Gersabeck, T. Gershon, P. Ghez, A. Gianelle, V. Gibson, L. Giubega, V. Gligorov, C. Gobel, D. Golubkov, A. Golutvin, A. Gomes, H. Gordon, M. G'andara, R. Diaz, L. Cardoso, E. Graug'es, G. Graziani, A. Grecu, E. Greening, S. Gregson, P. Griffith, L. Grillo, O. Grunberg, B. Gui, E. Gushchin, Y. Guz, T. Gys, C. Hadjivasiliou, G. Haefeli, C. Haen, T. Hafkenscheid, S. Haines, S. Hall, B. Hamilton, T. Hampson, S. Hansmann-Menzemer, N. Harnew, S. Harnew, J. Harrison, T. Hartmann, J. He, T. Head, V. Heijne, K. Hennessy, P. Henrard, J. Morata, E. Herwijnen, M. Heß, A. Hicheur, D. Hill, M. Hoballah, P. Hopchev, W. Hulsbergen, P. Hunt, T. Huse, N. Hussain, D. Hutchcroft, D. Hynds, V. Iakovenko, M. Idzik, P. Ilten, R. Jacobsson, A. Jaeger, E. Jans, P. Jaton, A. Jawahery, F. Jing, M. John, D. Johnson, C. Jones, C. Joram, B. Jost, N. Jurik, M. Kaballo, S. Kandybei, W. Kanso, M. Karacson, T. Karbach, I. Kenyon, T. Ketel, B. Khanji, S. Klaver, O. Kochebina, I. Komarov, R. Koopman, P. Koppenburg, M. Korolev, A. Kozlinskiy, L. Kravchuk, K. Kreplin, M. Kreps, G. Krocker, P. Krokovny, F. Kruse, M. Kucharczyk, V. Kudryavtsev, K. Kurek, T. Kvaratskheliya, V. Thi, D. Lacarrere, G. Lafferty, A. Lai, D. Lambert, R. Lambert, E. Lanciotti, G. Lanfranchi, C. Langenbruch, T. Latham, C. Lazzeroni, R. Gac, J. Leerdam, J. Lees, R. Lefèvre, A. Leflat, J. Lefranccois, S. Leo, O. Leroy, T. Lesiak, B. Leverington, Y. Li, M. Liles, R. Lindner, C. Linn, F. Lionetto, B. Liu, G. Liu, S. Lohn, I. Longstaff, J. Lopes, N. López-March, P. Lowdon, H. Lu, D. Lucchesi, J. Luisier, H. Luo, E. Luppi, O. Lupton, F. Machefert, I. Machikhiliyan, F. Maciuc, O. Maev, S. Malde, G. Manca, G. Mancinelli, J. Maratas, U. Marconi, P. Marino, R. Marki, J. Marks, G. Martellotti, A. Martens, A. S'anchez, M. Martinelli, D. Santos, D. Tostes, A. Massafferri, R. Matev, Z. Máthé, C. Matteuzzi, A. Mazurov, M. McCann, J. McCarthy, A. McNab, R. McNulty, B. McSkelly, B. Meadows, F. Meier, M. Meissner, M. Merk, D. Milanés, M. Minard, J. Rodriguez, S. Monteil, D. Moran, M. Morandin, P. Morawski, A. Mordà, M. Morello, R. Mountain, I. Mous, F. Muheim, K. Muller, R. Mureşan, B. Muryn, B. Muster, P. Naik, T. Nakada, R. Nandakumar, I. Nasteva, M. Needham, S. Neubert, N. Neufeld, A. Nguyen, T. Nguyen, C. Nguyen-Mau, M. Nicol, V. Niess, R. Niet, N. Nikitin, T. Nikodem, A. Novoselov, A. Oblakowska-Mucha, V. Obraztsov, S. Oggero, S. Ogilvy, O. Okhrimenko, R. Oldeman, G. Onderwater, M. Orlandea, J. Goicochea, P. Owen, A. Oyanguren, B. Pal, A. Palano, M. Palutan, J. Panman, A. Papanestis, M. Pappagallo, L. Pappalardo, C. Parkes, C. Parkinson, G. Passaleva, G. Patel, M. Patel, C. Patrignani, C. Pavel-Nicorescu, A. Alvarez, A. Pearce, A. Pellegrino, G. Penso, M. Altarelli, S. Perazzini, E. Trigo, P. Perret, M. Perrin-Terrin, L. Pescatore, E. Pesen, G. Pessina, K. Petridis, A. Petrolini, E. Olloqui, B. Pietrzyk, T. Pilavr, D. Pinci, A. Pistone, S. Playfer, M. Casasus, F. Polci, G. Polok, A. Poluektov, E. Polycarpo, A. Popov, D. Popov, B. Popovici, C. Potterat, A. Powell, J. Prisciandaro, A. Pritchard, C. Prouve, V. Pugatch, A. Navarro, G. Punzi, W. Qian, B. Rachwal, J. Rademacker, B. Rakotomiaramanana, M. Rama, M. Rangel, I. Raniuk, N. Rauschmayr, G. Raven, S. Redford, S. Reichert, M. Reid, A. Reis, S. Ricciardi, A. Richards, K. Rinnert, V. Molina, D. Romero, P. Robbe, D. Roberts, A. Rodrigues, E. Rodrigues, P. Perez, S. Roiser, V. Romanovsky, A. Vidal, M. Rotondo, J. Rouvinet, T. Ruf (2014)

    Updated measurements of exclusive J/ψ and ψ(2S) production cross-sections in pp collisions at √s = 7 TeV

    Journal of Physics G, 41

  • A. Adeluyi, C. Bertulani (2011)

    Constraining gluon shadowing using photoproduction in ultraperipheral pA and AA collisions

    Physical Review C, 85

  • M. Klasen, Gustav Kramer (1995)

    Inclusive dijet production at HERA: direct photon cross sections in next-to-leading order QCD

    Zeitschrift für Physik C: Particles and Fields, 72

  • S. Klein (2018)

    Two-photon production of dilepton pairs in peripheral heavy ion collisions

    arXiv: Nuclear Theory

  • (2014)

    055002 [arXiv:1401.3288 [hep-ex]

  • K. Eskola, Petja Paakkinen, H. Paukkunen, C. Salgado (2016)

    EPPS16: nuclear parton distributions with LHC data

    The European Physical Journal. C, Particles and Fields, 77

  • E. Abbas, B. Abelev, J. Adam, D. Adamová, A. Adare, M. Aggarwal, G. Rinella, M. Agnello, A. Agocs, A. Agostinelli, Z. Ahammed, N. Ahmad, A. Masoodi, I. Ahmed, S. Ahn, S. Ahn, I. Aimo, M. Ajaz, A. Akindinov, D. Aleksandrov, B. Alessandro, D. Alexandre, A. Alici, A. Alkin, E. Aviña, J. Alme, T. Alt, V. Altini, S. Altinpinar, I. Altsybeev, C. Andrei, A. Andronic, V. Anguelov, J. Anielski, C. Anson, T. Antičić, F. Antinori, P. Antonioli, L. Aphecetche, H. Appelshäuser, N. Arbor, S. Arcelli, A. Arend, N. Armesto, R. Arnaldi, T. Aronsson, I. Arsene, M. Arslandok, A. Asryan, A. Augustinus, R. Averbeck, T. Awes, J. Äystö, M. Azmi, M. Bach, A. Badalà, Y. Baek, R. Bailhache, R. Bala, A. Baldisseri, F. Pedrosa, J. Ban, R. Baral, R. Barbera, F. Barile, G. Barnaföldi, L. Barnby, V. Barret, J. Bartke, M. Basile, N. Bastid, S. Basu, B. Bathen, G. Batigne, B. Batyunya, P. Batzing, C. Baumann, I. Bearden, H. Beck, N. Behera, I. Belikov, F. Bellini, R. Bellwied, E. Belmont-Moreno, G. Bencédi, S. Beole, I. Berceanu, A. Bercuci, Y. Berdnikov, D. Berényi, A. Bergognon, R. Bertens, D. Berzano, L. Betev, A. Bhasin, A. Bhati, J. Bhom, L. Bianchi, N. Bianchi, C. Bianchin, J. Bielcik, J. Bielčíková, A. Bilandzic, S. Bjelogrlić, F. Blanco, F. Blanco, D. Blau, C. Blume, M. Boccioli, S. Böttger, A. Bogdanov, H. Boggild, M. Bogolyubsky, L. Boldizsár, M. Bombara, J. Book, H. Borel, A. Borissov, F. Bossù, M. Botje, E. Botta, E. Braidot, P. Braun-Munzinger, M. Bregant, T. Breitner, T. Broker, T. Browning, M. Broz, R. Brun, E. Bruna, G. Bruno, D. Budnikov, H. Buesching, S. Bufalino, P. Buncic, O. Busch, Z. Buthelezi, D. Caffarri, X. Cai, H. Caines, E. Villar, P. Camerini, V. Roman, G. Romeo, W. Carena, F. Carena, N. Filho, F. Carminati, A. Díaz, J. Castellanos, J. Hernandez, E. Casula, V. Catanescu, C. Cavicchioli, C. Sanchez, J. Čepila, P. Cerello, B. Chang, S. Chapeland, J. Charvet, S. Chattopadhyay, S. Chattopadhyay, M. Cherney, C. Cheshkov, B. Cheynis, V. Barroso, D. Chinellato, P. Chochula, M. Chojnacki, S. Choudhury, P. Christakoglou, C. Christensen, P. Christiansen, T. Chujo, S. Chung, C. Cicalò, L. Cifarelli, F. Cindolo, J. Cleymans, F. Colamaria, D. Colella, A. Collu, G. Balbastre, Z. Valle, M. Connors, G. Contin, J. Contreras, T. Cormier, Y. Morales, P. Cortese, I. Maldonado, M. Cosentino, F. Costa, M. Cotallo, E. Crescio, P. Crochet, E. Alaniz, R. Albino, E. Cuautle, L. Cunqueiro, A. Dainese, R. Dang, A. Danu, K. Das, I. Das, S. Das, D. Das, S. Dash, A. Dash, S. De, G. Barros, A. Caro, G. Cataldo, J. Cuveland, A. Falco, D. Gruttola, H. Delagrange, A. Deloff, N. Marco, E. Denes, S. Pasquale, A. Deppman, G. Erasmo, R. Rooij, M. Corchero, D. Bari, T. Dietel, C. Giglio, S. Liberto, A. Mauro, P. Nezza, R. Divià, Ø. Djuvsland, A. Dobrin, T. Dobrowolski, B. Dönigus, O. Dordic, A. Dubey, A. Dubla, L. Ducroux, P. Dupieux, A. Majumdar, D. Elia, D. Emschermann, H. Engel, B. Erazmus, H. Erdal, D. Eschweiler, B. Espagnon, M. Estienne, S. Esumi, D. Evans, S. Evdokimov, G. Eyyubova, D. Fabris, J. Faivre, D. Falchieri, A. Fantoni, M. Fasel, D. Fehlker, L. Feldkamp, D. Felea, A. Feliciello, B. Fenton-Olsen, G. Feofilov, A. Tèllez, A. Ferretti, A. Festanti, J. Figiel, M. Figueredo, S. Filchagin, D. Finogeev, F. Fionda, E. Fiore, E. Floratos, M. Floris, S. Foertsch, P. Foka, S. Fokin, E. Fragiacomo, A. Francescon, U. Frankenfeld, U. Fuchs, C. Furget, M. Girard, J. Gaardhøje, M. Gagliardi, A. Gago, M. Gallio, D. Gangadharan, P. Ganoti, C. Garabatos, E. Garcia-Solis, C. Gargiulo, I. Garishvili, J. Gerhard, M. Germain, C. Geuna, M. Gheata, A. Gheata, B. Ghidini, P. Ghosh, P. Gianotti, P. Giubellino, E. Gladysz-dziadus, P. Glässel, R. Gomez, E. Ferreiro, L. González-Trueba, P. GONZÁLEZ-ZAMORA, S. Gorbunov, A. Goswami, S. Gotovac, L. Graczykowski, R. Grajcarek, A. Grelli, C. Grigoras, A. Grigoras, V. Grigoriev, A. Grigoryan, S. Grigoryan, B. Grinyov, N. Grion, P. Gros, J. Grosse-Oetringhaus, J. Grossiord, R. Grosso, F. Guber, R. Guernane, B. Guerzoni, M. Guilbaud, K. Gulbrandsen, H. Gulkanyan, T. Gunji, A. Gupta, R. Gupta, R. Haake, Ø. Haaland, C. Hadjidakis, M. Haiduc, H. Hamagaki, G. Hamar, B. Han, L. Hanratty, A. Hansen, Z. Harmanová-Tóthová, J. Harris, M. Hartig, A. Harton, D. Hatzifotiadou, S. Hayashi, A. Hayrapetyan, S. Heckel, M. Heide, H. Helstrup, A. Herghelegiu, G. Corral, N. Herrmann, B. Hess, K. Hetland, B. Hicks, B. Hippolyte, Y. Hori, P. Hristov, I. Hrivnácová, M. Huang, T. Humanic, D. Hwang, R. Ichou, R. Ilkaev, I. Ilkiv, M. Inaba, E. Incani, G. Innocenti, P. Innocenti, M. Ippolitov, M. Irfan, C. Ivan, M. Ivanov, A. Ivanov, V. Ivanov, O. Ivanytskyi, A. Jacholkowski, P. Jacobs, C. Jahnke, H. Jang, M. Janik, P. Jayarathna, S. Jena, D. Jha, R. Bustamante, P. Jones, H. Jung, A. Jusko, A. Kaidalov, S. Kalcher, P. Kalinak, T. Kalliokoski, A. Kalweit, J. Kang, V. Kaplin, S. Kar, A. Uysal, O. Karavichev, T. Karavicheva, E. Karpechev, A. Kazantsev, U. Kebschull, R. Keidel, B. Ketzer, M. Khan, P. Khan, S. Khan, K. Khan, A. Khanzadeev, Y. Kharlov, B. Kileng, M. Kim, T. Kim, B. Kim, S. Kim, M. Kim, D. Kim, J. Kim, J. Kim, D. Kim, S. Kirsch, I. Kisel, S. Kiselev, A. Kisiel, J. Klay, J. Klein, C. Klein-Bösing, M. Kliemant, A. Kluge, M. Knichel, A. Knospe, M. Köhler, T. Kollegger, A. Kolojvari, M. Kompaniets, V. Kondratiev, N. Kondratyeva, A. Konevskikh, V. Kovalenko, M. Kowalski, S. Kox, G. Meethaleveedu, J. Kral, I. Králik, F. Kramer, A. Kravčáková, M. Krelina, M. Kretz, M. Krivda, F. Krizek, M. Krůs, E. Kryshen, M. Krzewicki, V. Kučera, Y. Kucheriaev, T. Kugathasan, C. Kuhn, P. Kuijer, I. Kulakov, J. Kumar, P. Kurashvili, A. Kurepin, A. Kurepin, A. Kuryakin, V. Kushpil, S. Kushpil, H. Kvaerno, M. Kweon, Y. Kwon, P. Guevara, C. Fernandes, I. Lakomov, R. Langoy, S. Pointe, C. Lara, A. Lardeux, P. Rocca, R. Lea, M. Lechman, S. Lee, G. Lee, I. Legrand, J. Lehnert, R. Lemmon, M. Lenhardt, V. Lenti, H. Leon, M. Leoncino, I. Monzón, P. Lévai, S. Li, J. Lien, R. Lietava, S. Lindal (2013)

    Charmonium and e+e− pair photoproduction at mid-rapidity in ultra-peripheral Pb–Pb collisions at \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin

    The European Physical Journal. C, Particles and Fields, 73

  • J. Fernandez, J. Fernandez, C. Adolphsen, A. Akay, H. Aksakal, J. Albacete, S. Alekhin, P. Allport, V. Andreev, Robert Appleby, Robert Appleby, E. Arikan, N. Armesto, G. Azuelos, G. Azuelos, M. Bai, D. Barber, D. Barber, J. Bartels, O. Behnke, J. Behr, A. Belyaev, A. Belyaev, I. Ben-Zvi, N. Bernard, S. Bertolucci, S. Bettoni, S. Biswal, J. Blümlein, H. Böttcher, A. Bogacz, C. Bracco, G. Brandt, H. Braun, S. Brodsky, O. Brüning, E. Bulyak, A. Buniatyan, H. Burkhardt, I. Cakir, O. Cakir, R. Calaga, V. Çeti̇nkaya, E. Ciapala, R. Ciftci, A. Ciftci, B. Cole, John Collins, O. Dadoun, J. Dainton, A. Roeck, D. d’Enterria, A. Dudarev, Å. Eide, R. Enberg, E. Eroglu, K. Eskola, L. Favart, M. Fitterer, S. Forte, A. Gaddi, P. Gambino, H. Morales, T. Gehrmann, P. Gladkikh, C. Glasman, R. Godbole, B. Goddard, T. Greenshaw, A. Guffanti, V. Guzey, V. Guzey, C. Gwenlan, T. Han, Y. Hao, F. Haug, W. Herr, A. Herv'e, B. Holzer, M. Ishitsuka, M. Jacquet, B. Jeanneret, J. Jiménez, J. Jowett, H. Jung, H. Karadeni̇z, D. Kayran, A. Kilic, K. Kimura, M. Klein, U. Klein, T. Kluge, F. Kocak, M. Korostelev, A. Kosmicki, P. Kostka, H. Kowalski, G. Kramer, D. Kuchler, M. Kuze, T. Lappi, P. Laycock, E. Levichev, S. Levonian, V. Litvinenko, A. Lombardi, J. Maeda, C. Marquet, B. Mellado, K. Mess, A. Milanese, S. Moch, I. Morozov, Y. Muttoni, S. Myers, S. Nandi, Z. Nergiz, P. Newman, T. Omori, J. Osborne, E. Paoloni, Y. Papaphilippou, C. Pascaud, H. Paukkunen, E. Perez, T. Pieloni, E. Piliçer, B. Pire, R. Plačakytė, A. Polini, V. Ptitsyn, Y. Pupkov, V. Radescu, S. Raychaudhuri, L. Rinolfi, R. Rohini, J. Rojo, S. Russenschuck, M. Şahin, C. Salgado, K. Sampei, R. Sassot, E. Sauvan, U. Schneekloth, T. Schörner-Sadenius, D. Schulte, A. Senol, A. Seryi, P. Sievers, A. Skrinsky, W. Smith, H. Spiesberger, A. Staśto, M. Strikman, M. Sullivan, S. Sultansoy, Yipeng Sun, B. Surrow, L. Szymanowski, P. Taels, I. Tapan, T. Tasci, E. Tassi, H. Kate, J. Terron, H. Thiesen, L. Thompson, L. Thompson, K. Tokushuku, R. Garc'ia, D. Tommasini, D. Trbojevic, N. Tsoupas, J. Tuckmantel, S. Turkoz, T. Trinh, K. Tywoniuk, G. Unel, J. Urakawa, P. Vanmechelen, A. Variola, R. Veness, A. Vivoli, P. Vobly, J. Wagner, R. Wallny, S. Wallon, G. Watt, C. Weiss, U. Wiedemann, U. Wienands, F. Willeke, B. Xiao, V. Yakimenko, A. Żarnecki, Zhen Zhang, F. Zimmermann, R. Žlebčík, F. Zomer (2012)

    A Large Hadron Electron Collider at CERN: Report on the Physics and Design Concepts for Machine and Detector

    Journal of Physics G, 39

  • M. Glück, E. Reya, A. Vogt (1992)

    Photonic parton distributions.

    Physical review. D, Particles and fields, 46 5

  • 조남욱 (2003)

    전자/제조업의 Collaboration 전략

    , 10

  • L. Frankfurt, V. Guzey, M. Strikman (2011)

    Leading twist nuclear shadowing phenomena in hard processes with nuclei

    arXiv: High Energy Physics - Phenomenology

  • S. Fichet, G. Gersdorff, B. Lenzi, C. Royon, M. Saimpert (2014)

    Light-by-light scattering with intact protons at the LHC: from standard model to new physics

    Journal of High Energy Physics, 2015

  • E. Basso, V. Gonçalves, A. Kohara, M. Rangel (2017)

    Photon and Pomeron-induced Production of Dijets in pp, pA and AA Collisions

    The European Physical Journal C, 77

  • D. d’Enterria, G. Silveira (2013)

    Observing light-by-light scattering at the Large Hadron Collider.

    Physical review letters, 111 8

  • R. Aaij, B. Adeva, M. Adinolfi, A. Affolder, Z. Ajaltouni, S. Akar, J. Albrecht, Federico Alessio, M. Alexander, S. Ali, G. Alkhazov, P. Cartelle, A. Alves, S. Amato, S. Amerio, Y. Amhis, L. An, L. Anderlini, J. Anderson, M. Andreotti, J. Andrews, R. Appleby, O. Gutiérrez, F. Archilli, P. d’Argent, A. Artamonov, M. Artuso, E. Aslanides, G. Auriemma, M. Baalouch, S. Bachmann, J. Back, A. Badalov, C. Baesso, W. Baldini, R. Barlow, C. Barschel, S. Barsuk, W. Barter, V. Batozskaya, V. Battista, A. Bay, L. Beaucourt, J. Beddow, F. Bedeschi, I. Bediaga, L. Bel, I. Belyaev, E. Ben-Haim, G. Bencivenni, S. Benson, J. Benton, A. Berezhnoy, R. Bernet, A. Bertolin, M. Bettler, M. Beuzekom, A. Bieñ, S. Bifani, T. Bird, A. Birnkraut, A. Bizzeti, T. Blake, F. Blanc, J. Blouw, S. Blusk, V. Bocci, A. Bondar, N. Bondar, W. Bonivento, S. Borghi, M. Borsato, T. Bowcock, E. Bowen, C. Bozzi, S. Braun, D. Brett, M. Britsch, T. Britton, J. Brodzicka, N. Brook, A. Bursche, J. Buytaert, S. Cadeddu, R. Calabrese, M. Calvi, M. Gomez, P. Campana, D. Perez, L. Capriotti, A. Carbone, G. Carboni, R. Cardinale, A. Cardini, P. Carniti, L. Carson, K. Akiba, R. Mohr, G. Casse, L. Cassina, L. García, M. Cattaneo, C. Cauet, G. Cavallero, R. Cenci, M. Charles, P. Charpentier, M. Chefdeville, S. Chen, S. Cheung, N. Chiapolini, M. Chrzaszcz, X. Vidal, G. Ciezarek, P. Clarke, M. Clemencic, H. Cliff, J. Closier, V. Coco, J. Cogan, E. Cogneras, V. Cogoni, L. Cojocariu, G. Collazuol, P. Collins, A. Comerma-Montells, A. Contu, A. Cook, M. Coombes, S. Coquereau, G. Corti, M. Corvo, B. Couturier, G. Cowan, D. Craik, A. Crocombe, M. Torres, S. Cunliffe, R. Currie, C. D’Ambrosio, J. Dalseno, P. David, A. Davis, K. Bruyn, S. Capua, M. Cian, J. Miranda, L. Paula, W. Silva, P. Simone, C. Dean, D. Decamp, M. Deckenhoff, L. Buono, N. Déléage, D. Derkach, O. Deschamps, F. Dettori, B. Dey, A. Canto, F. Ruscio, H. Dijkstra, S. Donleavy, F. Dordei, M. Dorigo, A. Suárez, D. Dossett, A. Dovbnya, K. Dreimanis, G. Dujany, F. Dupertuis, P. Durante, R. Dzhelyadin, A. Dziurda, A. Dzyuba, S. Easo, U. Egede, V. Egorychev, S. Eidelman, S. Eisenhardt, U. Eitschberger, R. Ekelhof, L. Eklund, I. Rifai, C. Elsasser, S. Ely, S. Esen, H. Evans, T. Evans, A. Falabella, C. Färber, C. Farinelli, N. Farley, S. Farry, R. Fay, D. Ferguson, V. Albor, F. Ferrari, F. Rodrigues, M. Ferro-Luzzi, S. Filippov, M. Fiore, M. Fiorini, M. Firlej, C. Fitzpatrick, T. Fiutowski, P. Fol, M. Fontana, F. Fontanelli, R. Forty, O. Francisco, M. Frank, C. Frei, M. Frosini, J. Fu, E. Furfaro, A. Torreira, D. Galli, S. Gallorini, S. Gambetta, M. Gandelman, P. Gandini, Y. Gao, J. Pardiñas, J. Garofoli, J. Ticó, L. Garrido, D. Gascón, C. Gaspar, U. Gastaldi, R. Gauld, L. Gavardi, G. Gazzoni, A. Geraci, D. Gerick, E. Gersabeck, M. Gersabeck, T. Gershon, P. Ghez, A. Gianelle, S. Gianì, V. Gibson, L. Giubega, V. Gligorov, C. Göbel, D. Golubkov, A. Golutvin, A. Gomes, C. Gotti, M. Gándara, R. Diaz, L. Cardoso, E. Grauges, E. Graverini, G. Graziani, A. Grecu, E. Greening, S. Gregson, P. Griffith, L. Grillo, O. Grünberg, B. Gui, E. Gushchin, Y. Guz, T. Gys, C. Hadjivasiliou, G. Haefeli, C. Haen, S. Haines, S. Hall, B. Hamilton, T. Hampson, X. Han, S. Hansmann-Menzemer, N. Harnew, S. Harnew, J. Harrison, J. He, T. Head, V. Heijne, K. Hennessy, P. Henrard, L. Henry, J. Morata, E. Herwijnen, M. Heß, A. Hicheur, D. Hill, M. Hoballah, P. Hopchev, W. Hulsbergen, T. Humair, N. Hussain, D. Hutchcroft, D. Hynds, M. Idzik, P. Ilten, R. Jacobsson, A. Jaeger, J. Jalocha, E. Jans, A. Jawahery, F. Jing, M. John, D. Johnson, C. Jones, C. Joram, B. Jost, N. Jurik, S. Kandybei, W. Kanso, M. Karacson, T. Karbach, S. Karodia, M. Kelsey, I. Kenyon, M. Kenzie, T. Ketel, B. Khanji, C. Khurewathanakul, S. Klaver, K. Klimaszewski, O. Kochebina, M. Kolpin, I. Komarov, R. Koopman, P. Koppenburg, M. Korolev, L. Kravchuk, K. Kreplin, M. Kreps, G. Krocker, P. Krokovny, F. Kruse, W. Kucewicz, M. Kucharczyk, V. Kudryavtsev, K. Kurek, T. Kvaratskheliya, V. Thi, D. Lacarrere, G. Lafferty, A. Lai, D. Lambert, R. Lambert, G. Lanfranchi, C. Langenbruch, B. Langhans, T. Latham, C. Lazzeroni, R. Gac, J. Leerdam, J. Lees, R. Lefèvre, A. Leflat, J. Lefrancois, O. Leroy, T. Lesiak, B. Leverington, Y. Li, T. Likhomanenko, M. Liles, R. Lindner, C. Linn, F. Lionetto, B. Liu, S. Lohn, I. Longstaff, J. Lopes, D. Lucchesi, M. Martinez, H. Luo, A. Lupato, E. Luppi, O. Lupton, F. Machefert, F. Maciuc, O. Maev, S. Malde, A. Malinin, G. Manca, G. Mancinelli, P. Manning, A. Mapelli, J. Maratas, J. Marchand, U. Marconi, C. Benito, P. Marino, R. Märki, J. Marks, G. Martellotti, M. Martinelli, D. Santos, F. Vidal, D. Tostes, A. Massafferri, R. Matev, A. Mathad, Z. Máthé, C. Matteuzzi, K. Matthieu, A. Mauri, B. Maurin, A. Mazurov, M. McCann, J. McCarthy, A. McNab, R. McNulty, B. Meadows, F. Meier, M. Meissner, M. Merk, D. Milanés, M. Minard, D. Mitzel, J. Rodriguez, S. Monteil, M. Morandin, P. Morawski, A. Mordà, M. Morello, J. Moroń, A. Morris, R. Mountain, F. Muheim, J. Müller, K. Müller, V. Müller, M. Mussini, B. Muster, P. Naik, T. Nakada, R. Nandakumar, I. Nasteva, M. Needham, N. Neri, S. Neubert, N. Neufeld, M. Neuner, A. Nguyen, T. Nguyen, C. Nguyen-Mau, V. Niess, R. Niet, N. Nikitin, T. Nikodem, D. Ninci, A. Novoselov, D. O’Hanlon, A. Oblakowska-Mucha, V. Obraztsov, S. Ogilvy, O. Okhrimenko, R. Oldeman, C. Onderwater, B. Rodrigues, J. Goicochea, A. Otto, P. Owen, A. Oyanguren, A. Palano, F. Palombo, M. Palutan, J. Panman, A. Papanestis, M. Pappagallo, L. Pappalardo, C. Parkes, G. Passaleva, G. Patel, M. Patel, C. Patrignani, A. Pearce, A. Pellegrino, G. Penso, M. Altarelli, S. Perazzini, P. Perret, L. Pescatore, K. Petridis, A. Petrolini, M. Petruzzo, E. Olloqui, B. Pietrzyk, T. Pilař, D. Pinci, A. Pistone, S. Playfer, M. Casasus, T. Poikela, F. Polci, A. Poluektov, I. Polyakov, E. Polycarpo, A. Popov, D. Popov, B. Popovici, C. Potterat, E. Price (2015)

    Measurement of the exclusive Υ production cross-section in pp collisions at s=7$$ \sqrt{s}=7 $$ TeV and 8 TeV

    Journal of High Energy Physics, 2015

  • A. Hameren, M. Kłusek-Gawenda, A. Szczurek (2017)

    Single- and double-scattering production of four muons in ultraperipheral $PbPb$ collisions at the Large Hadron Collider

    Physics Letters B, 776

  • P. Kotko, K. Kutak, S. Sapeta, A. Staśto, M. Strikman (2017)

    Estimating nonlinear effects in forward dijet production in ultra-peripheral heavy ion collisions at the LHC

    The European Physical Journal C, 77

  • M. Ryskin (1993)

    DiffractiveJ/Ψ electroproduction in LLA QCD

    Zeitschrift für Physik C Particles and Fields, 57

  • .lhcb Collaboration

  • J. Nystrand (2004)

    Electromagnetic interactions in nucleus-nucleus and proton-proton collisions

    Nuclear Physics, 752

  • T. Lappi, H. Mantysaari (2013)

    $J/|psi$ production in ultraperipheral Pb+Pb and $p$+Pb collisions at energies available at the CERN Large Hadron Collider

    Physical Review C, 87

  • V. Khachatryan, D. Anderson, A. Apresyan, J. Bendavid, A. Bornheim, J. Bunn, Y. Chen, Javier Duarte, A. Mott, H. Newman, C. Peña, M. Spiropulu, J. Vlimant, S. Xie, R. Zhu (2017)

    Coherent J/ψ photoproduction in ultra-peripheral PbPb collisions at √s_NN = 2.76 TeV with the CMS experiment

  • (1998)

    arXiv:hep-ph/9712256. M. Klasen and G. Kramer,

  • (2012)

    LHeC Study Group

  • L. Frankfurt, V. Guzey, M. Strikman, M. Zhalov (2015)

    Nuclear shadowing in photoproduction of ρ mesons in ultraperipheral nucleus collisions at RHIC and the LHC

    Physics Letters B, 752

  • C. Salgado, J. Alvarez-Muñiz, F. Arleo, N. Armesto, M. Botje, M. Cacciari, J. Campbell, C. Carli, B. Cole, D. d’Enterria, F. Gelis, V. Guzey, K. Hencken, P. Jacobs, J. Jowett, S. Klein, F. Maltoni, A. Morsch, K. Piotrzkowski, J. Qiu, T. Satogata, F. Siklér, M. Strikman, H. Takai, R. Vogt, R. Vogt, J. Wessels, S. White, U. Wiedemann, B. Wyslouch, M. Zhalov (2011)

    Proton–nucleus collisions at the LHC: scientific opportunities and requirements

    Journal of Physics G, 39

  • V. Rebyakova, M. Strikman, M. Zhalov (2011)

    Coherent ρ and J/ψ photoproduction in ultraperipheral processes with electromagnetic dissociation of heavy ions at RHIC and LHC

    Physics Letters B, 710

  • A. Kusina, K. Kovářík, T. Ježo, Benjamin Clark, C. Keppel, F. Lyonnet, J. Morfín, F. Olness, J. Owens, I. Schienbein, J. Yu (2015)

    nCTEQ15 - Global analysis of nuclear parton distributions with uncertainties

    arXiv: High Energy Physics - Phenomenology

  • J. Balewski, M. Betancourt, R. Corliss, J. Hays-Wehle, W. Leight, R. Milner, R. Redwine, J. Seele, S. Steadman, B. Surrow, G. Nieuwenhuizen, M. Walker (2012)

    ρ[superscript 0] photoproduction in AuAu collisions at √sNN=62.4 GeV measured with the STAR detector

  • J. Adam, D. Adamová, M. Aggarwal, G. Rinella, M. Agnello, N. Agrawal, Z. Ahammed, S. Ahn, I. Aimo, S. Aiola, M. Ajaz, A. Akindinov, S. Alam, D. Aleksandrov, B. Alessandro, D. Alexandre, R. Molina, A. Alici, A. Alkin, J. Alme, T. Alt, S. Altinpinar, I. Altsybeev, C. Prado, C. Andrei, A. Andronic, V. Anguelov, J. Anielski, T. Antičić, F. Antinori, P. Antonioli, L. Aphecetche, H. Appelshäuser, S. Arcelli, N. Armesto, R. Arnaldi, T. Aronsson, I. Arsene, M. Arslandok, A. Augustinus, R. Averbeck, M. Azmi, M. Bach, A. Badalà, Y. Baek, S. Bagnasco, R. Bailhache, R. Bala, A. Baldisseri, F. Pedrosa, R. Baral, A. Barbano, R. Barbera, F. Barile, G. Barnaföldi, L. Barnby, V. Barret, P. Bartalini, K. Barth, J. Bartke, E. Bartsch, M. Basile, N. Bastid, S. Basu, B. Bathen, G. Batigne, A. Camejo, B. Batyunya, P. Batzing, I. Bearden, H. Beck, C. Bedda, N. Behera, I. Belikov, F. Bellini, H. Martinez, R. Bellwied, R. Belmont, E. Belmont-Moreno, V. Belyaev, G. Bencédi, S. Beole, I. Berceanu, A. Bercuci, Y. Berdnikov, D. Berényi, R. Bertens, D. Berzano, L. Betev, A. Bhasin, I. Bhat, A. Bhati, B. Bhattacharjee, J. Bhom, L. Bianchi, N. Bianchi, C. Bianchin, J. Bielcik, J. Bielčíková, A. Bilandzic, R. Biswas, S. Biswas, S. Bjelogrlić, F. Blanco, D. Blau, C. Blume, F. Bock, A. Bogdanov, H. Boggild, L. Boldizsár, M. Bombara, J. Book, H. Borel, A. Borissov, M. Borri, F. Bossù, M. Botje, E. Botta, S. Böttger, P. Braun-Munzinger, M. Bregant, T. Breitner, T. Broker, T. Browning, M. Broz, E. Brucken, E. Bruna, G. Bruno, D. Budnikov, H. Buesching, S. Bufalino, P. Buncic, O. Busch, Z. Buthelezi, J. Buxton, D. Caffarri, X. Cai, H. Caines, L. Diaz, A. Caliva, E. Villar, P. Camerini, F. Carena, W. Carena, J. Castellanos, A. Castro, E. Casula, C. Cavicchioli, C. Sanchez, J. Čepila, P. Cerello, B. Chang, S. Chapeland, M. Chartier, J. Charvet, S. Chattopadhyay, S. Chattopadhyay, V. Chelnokov, M. Cherney, C. Cheshkov, B. Cheynis, V. Barroso, D. Chinellato, P. Chochula, K. Choi, M. Chojnacki, S. Choudhury, P. Christakoglou, C. Christensen, P. Christiansen, T. Chujo, S. Chung, Z. Chunhui, C. Cicalò, L. Cifarelli, F. Cindolo, J. Cleymans, F. Colamaria, D. Colella, A. Collu, M. Colocci, G. Balbastre, Z. Valle, M. Connors, J. Contreras, T. Cormier, Y. Morales, I. Maldonado, P. Cortese, M. Cosentino, F. Costa, P. Crochet, R. Albino, E. Cuautle, L. Cunqueiro, T. Dahms, A. Dainese, A. Danu, D. Das, I. Das, Samir Das, A. Dash, S. Dash, S. De, A. Caro, G. Cataldo, J. Cuveland, A. Falco, D. Gruttola, N. Marco, S. Pasquale, A. Deisting, A. Deloff, E. Denes, G. D’erasmo, D. Bari, A. Mauro, P. Nezza, M. Corchero, T. Dietel, P. Dillenseger, R. Divià, Ø. Djuvsland, A. Dobrin, T. Dobrowolski, D. Gimenez, B. Dönigus, O. Dordic, A. Dubey, A. Dubla, L. Ducroux, P. Dupieux, R. Ehlers, D. Elia, H. Engel, B. Erazmus, F. Erhardt, D. Eschweiler, B. Espagnon, M. Estienne, S. Esumi, J. Eum, D. Evans, S. Evdokimov, G. Eyyubova, L. Fabbietti, D. Fabris, J. Faivre, A. Fantoni, M. Fasel, L. Feldkamp, D. Felea, A. Feliciello, G. Feofilov, J. Ferencei, A. Tèllez, E. Ferreiro, A. Ferretti, A. Festanti, J. Figiel, M. Figueredo, S. Filchagin, D. Finogeev, F. Fionda, E. Fiore, M. Fleck, M. Floris, S. Foertsch, P. Foka, S. Fokin, E. Fragiacomo, A. Francescon, U. Frankenfeld, U. Fuchs, C. Furget, A. Furs, M. Girard, J. Gaardhøje, M. Gagliardi, A. Gago, M. Gallio, D. Gangadharan, P. Ganoti, C. Gao, C. Garabatos, E. Garcia-Solis, C. Gargiulo, P. Gasik, M. Germain, A. Gheata, M. Gheata, P. Ghosh, Saroj Ghosh, P. Gianotti, P. Giubellino, P. Giubilato, E. Gladysz-dziadus, P. Glässel, A. Ramírez, P. GONZÁLEZ-ZAMORA, S. Gorbunov, L. Görlich, S. Gotovac, V. Grabski, L. Graczykowski, A. Grelli, A. Grigoras, C. Grigoras, V. Grigoriev, A. Grigoryan, S. Grigoryan, B. Grinyov, N. Grion, J. Grosse-Oetringhaus, J. Grossiord, R. Grosso, F. Guber, R. Guernane, B. Guerzoni, K. Gulbrandsen, H. Gulkanyan, T. Gunji, A. Gupta, R. Gupta, R. Haake, Ø. Haaland, C. Hadjidakis, M. Haiduc, H. Hamagaki, G. Hamar, L. Hanratty, A. Hansen, J. Harris, H. Hartmann, A. Harton, D. Hatzifotiadou, S. Hayashi, S. Heckel, M. Heide, H. Helstrup, A. Herghelegiu, G. Corral, B. Hess, K. Hetland, T. Hildén, H. Hillemanns, B. Hippolyte, P. Hristov, M. Huang, T. Humanic, N. Hussain, T. Hussain, D. Hutter, D. Hwang, R. Ilkaev, I. Ilkiv, M. Inaba, C. Ionita, M. Ippolitov, M. Irfan, M. Ivanov, V. Ivanov, V. Izucheev, P. Jacobs, C. Jahnke, H. Jang, M. Janik, P. Jayarathna, C. Jena, S. Jena, R. Bustamante, P. Jones, H. Jung, A. Jusko, P. Kalinak, A. Kalweit, J. Kamin, J. Kang, V. Kaplin, S. Kar, A. Uysal, O. Karavichev, T. Karavicheva, E. Karpechev, U. Kebschull, R. Keidel, D. Keijdener, M. Keil, K. Khan, M. Khan, P. Khan, S. Khan, A. Khanzadeev, Y. Kharlov, B. Kileng, B. Kim, D. Kim, D. Kim, H. Kim, J. Kim, M. Kim, M. Kim, S. Kim, T. Kim, S. Kirsch, I. Kisel, S. Kiselev, A. Kisiel, G. Kiss, J. Klay, C. Klein, J. Klein, C. Klein-Bösing, A. Kluge, M. Knichel, A. Knospe, T. Kobayashi, C. Kobdaj, M. Kofarago, T. Kollegger, A. Kolojvari, V. Kondratiev, N. Kondratyeva, E. Kondratyuk, A. Konevskikh, C. Kouzinopoulos, O. Kovalenko, V. Kovalenko, M. Kowalski, S. Kox, G. Meethaleveedu, J. Kral, I. Králik, A. Kravčáková, M. Krelina, M. Kretz, M. Krivda, F. Krizek, E. Kryshen, M. Krzewicki, A. Kubera, V. Kučera, T. Kugathasan, C. Kuhn, P. Kuijer, I. Kulakov, J. Kumar, L. Kumar, P. Kurashvili, A. Kurepin, A. Kurepin, A. Kuryakin, S. Kushpil, M. Kweon, Y. Kwon, S. Pointe, P. Rocca, C. Fernandes, I. Lakomov, R. Langoy, C. Lara, A. Lardeux, A. Lattuca, E. Laudi, R. Lea, L. Leardini, G. Lee, S. Lee, I. Legrand, R. Lemmon, V. Lenti, E. Leogrande, I. Monzón, M. Leoncino, P. Lévai, S. Li, X. Li, J. Lien, R. Lietava, S. Lindal, V. Lindenstruth, C. Lippmann, M. Lisa, H. Ljunggren, D. Lodato, P. Loenne, V. Loggins, V. Loginov, C. Loizides, X. Lopez, E. Torres, A. Lowe, P. Luettig, M. Lunardon, G. Luparello, P. Luz, A. Maevskaya, M. Mager, S. Mahajan, S. Mahmood (2015)

    Coherent ρ0 photoproduction in ultra-peripheral Pb-Pb collisions at sNN=2.76\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{docum

    Journal of High Energy Physics, 2015

  • C. Bertulani, S. Klein, J. Nystrand (2005)

    Physics of Ultra-Peripheral Nuclear Collisions

    Annual Review of Nuclear and Particle Science, 55

  • S. Jones, S. Jones, Alan Martin, M. Ryskin, M. Ryskin, T. Teubner (2015)

    Exclusive $J/\psi$ and $\Upsilon$ photoproduction and the low $x$ gluon

    Physics Letters B

  • M. Klasen, K. Kovářík (2018)

    Nuclear parton density functions from dijet photoproduction at the EIC

    Physical Review D

  • V. Gonçalves, B. Moreira, F. Navarra (2014)

    Investigation of diffractive photoproduction ofJ/Ψin hadronic collisions

    Physical Review C, 90

  • J. Takahashi, R. Souza (2008)

    Strangeness production in STAR

    arXiv: Nuclear Experiment

  • I. Helenius (2018)

    Simulations of photo-nuclear dijets with PYTHIA 8 and their sensitivity to nuclear PDFs

    Proceedings of XXVI International Workshop on Deep-Inelastic Scattering and Related Subjects — PoS(DIS2018)

  • K. Eskola, K. Eskola, H. Paukkunen, H. Paukkunen, C. Salgado (2009)

    EPS09: A New Generation of NLO and LO Nuclear Parton Distribution Functions

    Journal of High Energy Physics, 2009

  • K. Aamodt, N. Abel, A. Quintana, A. Acero, D. Adamová, M. Aggarwal, G. Rinella, A. Agocs, S. Salazar, Z. Ahammed, A. Ahmad, N. Ahmad, S. Ahn, R. Akimoto, A. Akindinov, D. Aleksandrov, B. Alessandro, R. Alfaro, A. Alici, E. Avina, J. Alme, T. Alt, S. Altinpinar, C. Andrei, A. Andronic, G. Anelli, V. Angelov, C. Anson, T. Antičić, K. Antipin, D. Antonczyk, F. Antinori, S. Antinori, P. Antonioli, A. Anzo, L. Aphecetche, H. Appelshäuser, S. Arcelli, R. Arceo, N. Armesto, R. Arnaldi, T. Aronsson, I. Arsene, A. Asryan, A. Augustinus, T. Awes, J. Äystö, M. Azmi, S. Bablok, A. Badalà, J. Baechler, Y. Baek, R. Bailhache, R. Bala, A. Baldisseri, A. Baldit, J. Ban, R. Barbera, G. Barnaföldi, L. Barnby, V. Barret, J. Bartke, M. Basile, V. Basmanov, N. Bastid, B. Bathen, G. Batigne, B. Batyunya, C. Baumann, I. Bearden, B. Becker, J. Belikov, R. Bellwied, E. Belmont-Moreno, A. Belogianni, L. Benhabib, S. Beole, I. Berceanu, A. Bercuci, E. Berdermann, Y. Berdnikov, L. Betev, A. Bhasin, A. Bhati, N. Bianchi, J. Bielcik, J. Bielčíková, A. Bilandzic, L. Bimbot, E. Biolcati, A. Blanc, F. Blanco, D. Blau, C. Blume, M. Boccioli, N. Bock, S. Böttger, A. Bogdanov, H. Boggild, M. Bogolyubsky, L. Boldizsár, M. Bombara, C. Bombonati, M. Bondila, H. Borel, V. Borshchov, S. Bose, M. Botje, G. Bourdaud, S. Bouvier, B. Boyer, M. Braun, P. Braun-Munzinger, L. Bravina, M. Bregant, T. Breitner, G. Bruckner, R. Brun, E. Bruna, G. Bruno, D. Budnikov, H. Buesching, K. Bugaev, P. Buncic, O. Busch, Z. Buthelezi, M. Cagliardi, X. Cai, H. Caines, I. Cali, E. Camacho, P. Camerini, R. Campagnolo, M. Campbell, V. Roman, X. Cao, G. Capitani, G. Romeo, M. Montes, F. Carena, W. Carena, F. Carminati, A. Dı́az, J. Castellanos, J. Hernandez, J. Castor, V. Catanescu, E. Cattaruzza, C. Caviacchiolo, P. Cerello, V. Cerný, V. Chambert, S. Chapeland, A. Charpy, J. Charvet, S. Chattopadhyay, M. Cherney, C. Cheshkov, B. Cheynis, E. Chiavassa, V. Barroso, D. Chinellato, P. Chochula, Kyungeon Choi, M. Chojnacki, P. Christakoglou, P. Christiansen, C. Christensen, C. Cicalò, L. Cifarelli, F. Cindolo, J. Cleymans, O. Cobanoglu, J. Coffin, A. Colla, E. Conner, G. Balbastre, Z. Valle, G. Contin, J. Contreras, T. Cormier, P. Cortese, I. Maldonado, F. Costa, P. Costantin, M. Cotallo, E. Crescio, P. Crochet, E. Cuautle, L. Cunqueiro, J. Cussonneau, H. Dalsgaard, A. Dainese, A. Danu, I. Das, S. Das, A. Dash, S. Dash, G. Barros, A. Caro, G. Cataldo, J. Cuveland, A. Falco, M. Gaspari, J. Groot, D. Gruttola, A. Haas, N. Marco, S. Pasquale, G. Vaux, H. Delagrange, G. Dellacasa, A. Deloff, V. Demanov, E. Denes, G. D’erasmo, D. Derkach, A. Devaux, D. Bari, C. Giglio, S. Liberto, A. Mauro, P. Nezza, M. Dialinas, L. Diaz, R. Diaz, T. Dietel, H. Ding, R. Divià, Djuvland, G. Valdiviesso, V. Dobretsov, A. Dobrin, T. Dobrowolski, B. Donigus, I. Dominguez, D. Don, O. Dordic, A. Dubey, L. Ducroux, P. Dupieux, A. Majumdar, M. Majumdar, P. Dwivedi, D. Elia, D. Emschermann, A. Enokizono, B. Espagnon, M. Estienne, S. Esumi, David Evans, S. Evrard, G. Eyyubova, C. Fabjan, D. Fabris, J. Faivre, D. Falchieri, A. Fantoni, M. Fasel, R. Fearick, A. Fedurov, V. Fekete, D. Felea, D. Fehlker, G. Feofilov, A. Téllez, A. Ferretti, A. Fick, M. Figueredo, S. Filchagin, C. Finck, R. Fini, E. Fiore, M. Floris, Z. Fodor, S. Foertsch, P. Foka, S. Fokin, P. Force, F. Formenti, E. Fragiacomo, M. Fragkiadakis, U. Frankenfeld, A. Frolov, U. Fuchs, C. Fumihiko, F. Furano, C. Furget, M. Girard, J. Gaardhøje, S. Gadrat, M. Gagliardi, A. Gago, M. Gallio, P. Ganoti, M. Ganti, C. Garabatos, J. Gebelein, R. Gemme, M. Germain, A. Gheata, M. Gheata, B. Ghidini, P. Ghosh, P. Giubellino, E. Gladysz-dziadus, R. Glasow, P. Glassel, A. Glenn, R. Gomez, E. González-Ferreiro, L. González-Trueba, P. GONZÁLEZ-ZAMORA, S. Gorbunov, Y. Gorbunov, S. Gotovac, H. Gottschlag, V. Grabski, N. Grion, A. Grigoras, C. Grigoras, V. Grigoriev, A. Grigoryan, P. Gros, J. Grosse-Oetringhaus, J. Grossiord, R. Grosso, B. Grynyov, C. Guarnaccia, F. Guber, R. Guernane, K. Gulbrandsen, H. Gulkanyan, T. Gunji, A. Gupta, R. Gupta, H. Gustafsson, H. Gutbrod, Haaland, C. Hadjidakis, M. Haiduc, G. Hamar, H. Hamagaki, J. Hamblen, B. Han, D. Hatzifotiadou, J. Harris, M. Hartig, A. Harutyunyan, A. Hayrapetyan, D. Hasch, D. Haşegan, H. Helstrup, M. Heinz, A. Herghelegiu, C. Hernández, G. Corral, N. Herrmann, K. Hetland, B. Hicks, P. Hille, B. Hippolyte, T. Horaguchi, Y. Hori, P. Hristov, S. Huber, I. Hrivnácová, S. Hu, T. Humanic, D. Hwang, R. Ichou, R. Ilkaev, I. Ilkiv, P. Innocenti, M. Ippolitov, M. Irfan, C. Ivan, A. Ivanov, M. Ivanov, V. Ivanov, P. Jacobs, A. Jacholkowski, S. Jangal, L. Jancurova, R. Janik, K. Jayananda, C. Jena, L. Jirden, G. Jones, Peter Jones, P. Jovanović, A. Jusko, H. Jung, W. Jung, S. Kalcher, T. Kalliokoski, A. Kalweit, A. Kamal, R. Kamermans, K. Kanaki, E. Kang, J. Kang, J. Kapitán, S. Kapusta, V. Kaplin, T. Karavicheva, E. Karpechev, A. Kazantsev, U. Kebschull, R. Keidel, S. Khan, A. Khanzadeev, Y. Kharlov, D. Kikoła, B. Kileng, D. Kim, D. Kim, Do Kim, H. Kim, J. Kim, Jonghyun Kim, M. Kim, S. Kim, Se Kim, S. Kirsch, I. Kisel, S. Kiselev, A. Kisiel, J. Klay, J. Klein, C. Klein-Bösing, M. Kliemant, A. Klovning, A. Kluge, S. Kniege, K. Koch, R. Kolevatov, A. Kolojvari, V. Kondratiev, N. Kondratyeva, E. Kornaś, R. Kour, M. Kowalski, S. Kox, K. Kozlov, J. Kral, I. Králik, F. Kramer, I. Kraus, A. Kravčáková, T. Krawutschke, M. Krivda, M. Krůs, E. Kryshen, M. Krzewicki, Y. Kucheriaev, C. Kuhn, P. Kuijer, L. Kumar, N. Kumar, P. Kurashvili, A. Kuryakin, A. Kurepin, A. Kurepin, S. Kushpil, V. Kushpil, M. Kutouski, Henning Kværnø, M. Kweon, Y. Kwon, F. Lackner, P. Guevara, V. Lafage, P. Rocca, C. Lara, D. Larsen, G. Laurenti, C. Lazzeroni, Y. Bornec, N. Bris, H. Lee, K. Lee, Sangeun Lee, F. Lefèvre, M. Lenhardt, L. Leistam, V. Lenti, H. Leon, I. Monzón, H. Vargas, P. Lévai, Xiang Li, R. Lietava, V. Lindenstruth, C. Lippmann, M. Lisa, O. Listratenko, L. Liu, Yunqi Liu, V. Loggins (2004)

    The ALICE Collaboration

  • V. Gonçalves, M. Jaime, D. Martins, M. Rangel (2018)

    Exclusive and diffractive $\mu^+ \mu^-$ production in $pp$ collisions at the LHC

    Physical Review D, 97

  • D. Ivanov, A. Schäfer, L. Szymanowski, G. Krasnikov (2004)

    Exclusive photoproduction of a heavy vector meson in QCD

    The European Physical Journal C - Particles and Fields, 34

  • M. Strikman, R. Vogt, S. White (2005)

    Probing Small x Parton Densities in Ultraperipheral AA and pA Collisions at the CERN Large Hadron Collider

    Physical Review Letters, 96

  • M. Klasen, G. Kramer (2011)

    Dijet photoproduction of massless charm jets at next-to-leading order of QCD

    The European Physical Journal C, 71

  • M. Klasen, G. Kramer (1996)

    Inclusive two-jet production at HERA: direct and resolved cross sections in next-to-leading order QCD

    Zeitschrift für Physik C Particles and Fields, 76

  • † for the CMS Collaboration

  • M. Kłusek-Gawenda, P. Lebiedowicz, A. Szczurek (2016)

    Light-by-light scattering in ultraperipheral Pb-Pb collisions at energies available at the CERN Large Hadron Collider

    Physical Review C, 93

  • S. Jones, Alan Martin, M. Ryskin, M. Ryskin, T. Teubner (2013)

    Probes of the small x gluon via exclusive J/ψ and Υ production at HERA and the LHC

    Journal of High Energy Physics, 2013

  • D. d’Enterria, G. Silveira (2016)

    Erratum: Observing Light-by-Light Scattering at the Large Hadron Collider [Phys. Rev. Lett. 111, 080405 (2013)].

    Physical review letters, 116 12

  • L. Aaij, C. Beteta, A. Adametz, B. Adeva, M. Adinolfi, C. Adrover, A. Affolder, Z. Ajaltouni, J. Albrecht, Federico Alessio, M. Alexander, S. Ali, G. Alkhazov, P. Cartelle, A. Alves, S. Amato, Y. Amhis, L. Anderlini, J. Anderson, R. Andreassen, R. Appleby, O. Gutierrez, F. Archilli, A. Artamonov, M. Artuso, E. Aslanides, G. Auriemma, S. Bachmann, J. Back, C. Baesso, V. Balagura, W. Baldini, R. Barlow, C. Barschel, S. Barsuk, W. Barter, T. Bauer, A. Bay, J. Beddow, I. Bediaga, S. Belogurov, K. Belous, I. Belyaev, E. Ben-Haim, M. Benayoun, G. Bencivenni, S. Benson, J. Benton, A. Berezhnoy, R. Bernet, M. Bettler, M. Beuzekom, A. Bieñ, S. Bifani, T. Bird, A. Bizzeti, P. Bjørnstad, T. Blake, F. Blanc, C. Blanks, J. Blouw, S. Blusk, A. Bobrov, V. Bocci, A. Bondar, N. Bondar, W. Bonivento, S. Borghi, A. Borgia, T. Bowcock, E. Bowen, C. Bozzi, T. Brambach, J. Brand, J. Bressieux, D. Brett, M. Britsch, T. Britton, N. Brook, H. Brown, I. Burducea, A. Bursche, J. Buytaert, S. Cadeddu, O. Callot, M. Calvi, M. Gomez, A. Camboni, P. Campana, A. Carbone, G. Carboni, R. Cardinale, A. Cardini, H. Carranza-Mejia, L. Carson, K. Akiba, G. Casse, M. Cattaneo, C. Cauet, M. Charles, P. Charpentier, P. Chen, N. Chiapolini, M. Chrzaszcz, K. Ciba, X. Vidal, G. Ciezarek, P. Clarke, M. Clemencic, H. Cliff, J. Closier, C. Coca, V. Coco, J. Cogan, E. Cogneras, P. Collins, A. Comerma-Montells, A. Contu, A. Cook, M. Coombes, G. Corti, B. Couturier, G. Cowan, D. Craik, S. Cunliffe, R. Currie, C. D’Ambrosio, P. David, P. David, I. Bonis, K. Bruyn, S. Capua, M. Cian, J. Miranda, L. Paula, W. Silva, P. Simone, D. Decamp, M. Deckenhoff, H. Degaudenzi, L. Buono, C. Deplano, D. Derkach, O. Deschamps, F. Dettori, A. Canto, J. Dickens, H. Dijkstra, P. Batista, M. Dogaru, F. Bonal, S. Donleavy, F. Dordei, A. Su'arez, D. Dossett, A. Dovbnya, F. Dupertuis, R. Dzhelyadin, A. Dziurda, A. Dzyuba, S. Easo, U. Egede, V. Egorychev, S. Eidelman, D. Eijk, S. Eisenhardt, U. Eitschberger, R. Ekelhof, L. Eklund, I. Rifai, C. Elsasser, D. Elsby, A. Falabella, C. Farber, G. Fardell, C. Farinelli, S. Farry, V. Fave, D. Ferguson, V. Albor, F. Rodrigues, M. Ferro-Luzzi, S. Filippov, C. Fitzpatrick, M. Fontana, F. Fontanelli, R. Forty, O. Francisco, M. Frank, C. Frei, M. Frosini, S. Furcas, E. Furfaro, A. Torreira, D. Galli, M. Gandelman, P. Gandini, Y. Gao, J. Garofoli, P. Garosi, J. Ticó, L. Garrido, C. Gaspar, R. Gauld, E. Gersabeck, M. Gersabeck, T. Gershon, P. Ghez, V. Gibson, V. Gligorov, C. Gobel, D. Golubkov, A. Golutvin, A. Gomes, H. Gordon, M. G'andara, R. Diaz, L. Cardoso, E. Graug'es, G. Graziani, A. Grecu, E. Greening, S. Gregson, O. Grunberg, B. Gui, E. Gushchin, Y. Guz, T. Gys, C. Hadjivasiliou, G. Haefeli, C. Haen, S. Haines, S. Hall, T. Hampson, S. Hansmann-Menzemer, N. Harnew, S. Harnew, J. Harrison, P. Harrison, T. Hartmann, J. He, V. Heijne, K. Hennessy, P. Henrard, J. Morata, E. Herwijnen, E. Hicks, D. Hill, M. Hoballah, P. Hopchev, P. Hopchev, W. Hulsbergen, P. Hunt, T. Huse, N. Hussain, D. Hutchcroft, D. Hynds, V. Iakovenko, P. Ilten, R. Jacobsson, A. Jaeger, E. Jans, F. Jansen, P. Jaton, F. Jing, M. John, D. Johnson, C. Jones, B. Jost, M. Kaballo, S. Kandybei, M. Karacson, T. Karbach, I. Kenyon, U. Kerzel, T. Ketel, A. Keune, B. Khanji, O. Kochebina, I. Komarov, R. Koopman, P. Koppenburg, M. Korolev, A. Kozlinskiy, L. Kravchuk, K. Kreplin, M. Kreps, G. Krocker, P. Krokovny, F. Kruse, M. Kucharczyk, V. Kudryavtsev, T. Kvaratskheliya, V. Thi, D. Lacarrere, G. Lafferty, A. Lai, D. Lambert, R. Lambert, E. Lanciotti, G. Lanfranchi, C. Langenbruch, T. Latham, C. Lazzeroni, R. Gac, J. Leerdam, J. Lees, R. Lefèvre, A. Leflat, J. Lefranccois, O. Leroy, Y. Li, L. Gioi, M. Liles, R. Lindner, C. Linn, B. Liu, G. Liu, J. Loeben, J. Lopes, E. Asamar, N. López-March, H. Lu, J. Luisier, H. Luo, F. Machefert, I. Machikhiliyan, F. Maciuc, O. Maev, S. Malde, G. Manca, G. Mancinelli, N. Mangiafave, U. Marconi, R. Marki, J. Marks, G. Martellotti, A. Martens, L. Martin, A. S'anchez, M. Martinelli, D. Santos, D. Tostes, A. Massafferri, R. Matev, Z. Máthé, C. Matteuzzi, M. Matveev, E. Maurice, A. Mazurov, J. McCarthy, R. McNulty, B. Meadows, F. Meier, M. Meissner, M. Merk, D. Milanés, M. Minard, J. Rodriguez, S. Monteil, D. Moran, P. Morawski, R. Mountain, I. Mous, F. Muheim, K. Muller, R. Mureşan, B. Muryn, B. Muster, P. Naik, T. Nakada, R. Nandakumar, I. Nasteva, M. Needham, N. Neufeld, A. Nguyen, T. Nguyen, C. Nguyen-Mau, M. Nicol, V. Niess, R. Niet, N. Nikitin, T. Nikodem, S. Nisar, A. Nomerotski, A. Novoselov, A. Oblakowska-Mucha, V. Obraztsov, S. Oggero, S. Ogilvy, O. Okhrimenko, R. Oldeman, M. Orlandea, J. Goicochea, P. Owen, B. Pal, A. Palano, M. Palutan, J. Panman, A. Papanestis, M. Pappagallo, C. Parkes, C. Parkinson, G. Passaleva, G. Patel, M. Patel, G. Patrick, C. Patrignani, C. Pavel-Nicorescu, A. Alvarez, A. Pellegrino, G. Penso, M. Altarelli, S. Perazzini, D. Perego, E. Trigo, A. Yzquierdo, P. Perret, M. Perrin-Terrin, G. Pessina, K. Petridis, A. Petrolini, A. Phan, E. Olloqui, B. Pietrzyk, T. Pilavr, D. Pinci, S. Playfer, M. Casasus, F. Polci, G. Polok, A. Poluektov, E. Polycarpo, D. Popov, B. Popovici, C. Potterat, A. Powell, J. Prisciandaro, V. Pugatch, A. Navarro, W. Qian, J. Rademacker, B. Rakotomiaramanana, M. Rangel, I. Raniuk, N. Rauschmayr, G. Raven, S. Redford, M. Reid, A. Reis, S. Ricciardi, A. Richards, K. Rinnert, V. Molina, D. Romero, P. Robbe, E. Rodrigues, P. Perez, G. Rogers, S. Roiser, V. Romanovsky, A. Vidal, J. Rouvinet, T. Ruf, H. Ruiz, G. Sabatino, J. Silva, N. Sagidova, P. Sail, B. Saitta, C. Salzmann, B. Sedes, M. Sannino, R. Santacesaria, C. Rios, E. Santovetti, M. Sapunov, A. Sarti, C. Satriano, A. Satta, M. Savrié, D. Savrina, P. Schaack, M. Schiller, H. Schindler, S. Schleich, M. Schlupp, M. Schmelling, B. Schmidt, O. Schneider, A. Schopper, M. Schune, R. Schwemmer, B. Sciascia, A. Sciubba, M. Seco, A. Semennikov, K. Senderowska, I. Sepp, N. Serra (2013)

    Exclusive J/ψ and ψ(2S) production in pp collisions at √s = 7 TeV

    Journal of Physics G, 40

  • V. Guzey, M. Zhalov (2013)

    Exclusive J/ψ production in ultraperipheral collisions at the LHC: constraints on the gluon distributions in the proton and nuclei

    Journal of High Energy Physics, 2013

ISSN
2469-9985
eISSN
ARCH-3335
DOI
10.1103/PhysRevC.99.065202
Publisher site
See Article on Publisher Site

Abstract

Inclusive dijet photoproduction in ultraperipheral heavy-ion collisions at the LHC in next-to-leading order QCD 1, 2, 3 4 V. Guzey and M. Klasen Department of Physics, University of Jyva¨skyla¨, P.O. Box 35, 40014 University of Jyva¨skyla¨, Finland Helsinki Institute of Physics, P.O. Box 64, 00014 University of Helsinki, Finland National Research Center “Kurchatov Institute”, Petersburg Nuclear Physics Institute (PNPI), Gatchina, 188300, Russia Institut fu¨r Theoretische Physik, Westfa¨lische Wilhelms-Universita¨t Mu¨nster, Wilhelm-Klemm-Straße 9, 48149 Mu¨nster, Germany We compute the cross section of inclusive dijet photoproduction in ultraperipheral Pb-Pb colli- sions at the LHC using next-to-leading order perturbative QCD. We demonstrate that our theoretical calculations provide a good description of various kinematic distributions measured by the ATLAS collaboration. We find that the calculated dijet photoproduction cross section is sensitive to nuclear modifications of parton distribution functions (PDFs) at the level of 10 to 20%. Hence, this process can be used to reduce uncertainties in the determination of these nuclear PDFs, whose current mag- nitude is comparable to the size of the calculated nuclear modifications of the dijet photoproduction cross section. I. INTRODUCTION Ultraperipheral collisions (UPCs) of relativistic ions correspond to large impact parameters between the nuclei exceeding the sum of their radii, so that short-range strong interactions between the ions are suppressed and reactions proceed rather via the emission of quasi-real photons by the colliding ions. Thus, UPCs allow one to study photon- photon and photon-hadron (proton, nucleus) interactions at high energies [1]. During the last decade, UPCs have become an active field of research, driven by experimental results obtained at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC), for a recent experimental review see, e.g., [2]. Notable examples of various UPC processes and their analyses include the two-photon production of dilepton pairs [3, 4]; light-by- light scattering γγ → γγ and searches for potential physics beyond the Standard Model [5–7]; an electromagnetic double-scattering contribution to dimuon pair production in photon-photon scattering [8]; exclusive photoproduction of charmonia in proton-proton [9, 10], proton-nucleus [11] and nucleus-nucleus [12–15] UPCs and of bottomonia in proton-proton [16] and proton-nucleus UPCs [17]; new constraints on the small-x gluon distribution in the proton [18, 19] and heavy nuclei [20, 21] and the dynamics of strong interactions at high energies in the color dipole framework [22–24]; and exclusive photoproduction of ρ mesons on nuclei [25–28] as well as tests of models of nuclear shadowing [29, 30]. Focusing on UPC studies of nuclear structure in QCD at the LHC, coherent J/ψ photoproduction in Pb-Pb UPCs at s = 2.76 TeV [12–15] revealed a significant nuclear suppression of the measured rapidity distributions. In NN the framework of the leading logarithmic approximation of perturbative QCD [31], it can be interpreted as evidence 2 2 −3 2 2 of large nuclear gluon shadowing, R = f (x, µ )/[Af (x, µ )] ≈ 0.6 at x = 10 and µ = 3 GeV (f g/A g/N g/A and f are gluon densities in Pb and the proton, respectively). This value of R agrees with predictions of g/N g the leading twist nuclear shadowing model [32], which are characterized by small theoretical uncertainties in this kinematic region. It is also broadly consistent with the EPS09 [33], nCTEQ15 [34], and EPPS16 [35] nuclear parton distribution functions (nPDFs), which however have significant uncertainties in this kinematic regime. Note that in the collinear factorization framework, next-to-leading order (NLO) perturbative QCD corrections to the cross section of J/ψ photoproduction are large [36, 37] and the relation between the gluon parton distribution function (PDF) and the gluon generalized parton distribution (GPD) is model-dependent, which makes it challenging to interpret the UPC data on J/ψ photoproduction on nuclei in terms of the NLO gluon nPDF. The program of UPC measurements continues with Run 2 at the LHC, where besides photoproduction of vector mesons, inclusive dijet photoproduction in Pb-Pb UPCs AA → A + 2jets + X has also recently been measured by the ATLAS collaboration [38] (for leading-order QCD predictions for rates of this process, see [39]). The cross section of this process is sensitive to quark and gluon nPDFs f (x, µ ) in a wide range of the momentum fraction x and j/A the resolution scale µ > O(20) GeV, where one still expects sizable nuclear modifications of the PDFs. In addition, imposing the requirement that the target nucleus stays intact, one can study diffractive dijet photoproduction in UPCs AA → A + 2jets + X + A. Studies of this process may shed some light on the mechanism of QCD factorization breaking in diffractive photoproduction and, for the first time, give access to nuclear diffractive PDFs [40, 41]. While further progress in constraining nPDFs will benefit from studies of high-energy hard processes with nuclei in proton- arXiv:1811.10236v2 [hep-ph] 5 Jul 2019 2 A γ Remnant Jet Jet Jet Jet (a) (b) FIG. 1: Typical leading-order Feynman graphs for dijet photoproduction in UPCs of hadrons A and B. Graphs (a) and (b) correspond to the direct and resolved photon contributions, respectively. nucleus (pA) scattering at the LHC [42] and lepton-nucleus (eA) scattering at a future Electron-Ion Collider (EIC) [43] and LHeC [44], UPCs at the LHC present an important and complimentary method of obtaining new constraints on nPDFs in a wide kinematic range already now. In this work, we make predictions for the cross section of inclusive dijet photoproduction in Pb-Pb UPCs at the LHC using NLO perturbative QCD [45] and nCTEQ15 nPDFs. We show that our approach provides a good description of various cross section distributions measured by the ATLAS collaboration [38]. Our analysis also shows that the dijet photoproduction cross section in the considered kinematics is sensitive to nuclear modifications of the PDFs. As a function of the momentum fraction x , the ratio of the cross sections calculated with nPDFs and in the impulse approximation behaves similarly to R for a given µ and deviates from unity by 10 − 20% for the central nCTEQ15 fit. The calculations using EPPS16 nPDFs and predictions of the leading twist nuclear shadowing model give similar results. This suggests that inclusive dijet photoproduction on nuclei can be used to reduce uncertainties in the determination of nPDFs, which are currently significant and comparable in size to the magnitude of the calculated nuclear modifications of the dijet photoproduction cross section. The remainder of this paper is structured as follows. In Sec. II, we outline the formalism of dijet photoproduction in UPCs using NLO perturbative QCD. We present and discuss our results for the LHC in Sec. III and draw conclusions in Sec. IV. II. PHOTOPRODUCTION OF DIJETS IN UPCS IN NLO PERTURBATIVE QCD Typical leading-order (LO) Feynman diagrams for dijet photoproduction in UPCs of nuclei A and B are shown in Fig. 1, where the graphs (a) and (b) correspond to the direct and resolved photon contributions, respectively. Note that beyond LO, the separation of the direct and resolved photon contributions depends on the factorization scheme and scale (see the discussion below). Using the Weizs¨acker-Williams method, which allows one to treat the electromagnetic field of an ultra-relativistic ion as a flux of equivalent quasi-real photons [1, 46], and the collinear factorization framework for photon-nucleus scattering, the cross section of the UPC process AB → A + 2jets + X is given by [45] dσ(AB → A + 2jets + X) = Z Z Z y 1 x X max A,max 2 2 dy dx dx f (y)f (x , µ )f (x , µ )dσˆ(ab → jets) , (1) γ A γ A γ/A a/γ b/B y 0 x min A,min a,b where a, b are parton flavors; f (y) is the flux of equivalent photons emitted by ion A, which depends on the γ/A photon light-cone momentum fraction y; f (x , µ ) is the PDF of the photon, which depends on the momentum a/γ γ fraction x and the factorization scale µ ; f (x , µ ) is the nuclear PDF with x being the corresponding parton γ A A b/B momentum fraction; and dσˆ(ab → jets) is the elementary cross section for production of two- and three-parton final states emerging as jets in hard scattering of partons a and b. The sum over a involves quarks and gluons for the resolved photon contribution and the photon for the direct photon contribution dominating at x ≈ 1. At LO, the γ 3 direct photon contribution has support exactly only at x = 1, i. e., f = δ(1 − x ). At NLO, the virtual and γ a γ γ real corrections are calculated with massless quarks in dimensional regularization, ultraviolet (UV) divergences are renormalized in the MS scheme, infrared (IR) divergences are canceled and factorized into the proton and photon PDFs, respectively. For the latter, this implies a transformation from the DIS into the MS scheme. The integration limits are determined by the rapidities and transverse momenta of the produced jets, see Sec. III. Note that Eq. (1) is based on the clear separation of scales, which characterize the long-distance electromagnetic interaction and the short-distance strong interaction. It generalizes the NLO perturbative QCD formalism of collinear factorization for jet photoproduction in lepton-proton scattering developed in Refs. [45, 47–49], which successfully described HERA ep data on dijet photoproduction [50]. Hence, Eq. (1) involves universal nuclear PDFs f (x , µ ), which can be b/B A accessed in a variety of hard processes involving nuclear targets [33–35], and the universal photon PDFs f (x , µ ), a/γ + − which are determined by e e data, for a review, see [45]. Hence, the interplay between the direct and resolved photon contributions in Eq. (1) is also universal and controlled by the standard µ evolution equations of photon PDFs and the choice of the factorization scheme. In our analysis, we used the following input for Eq. (1). For photon PDFs f (x , µ ), we used the GRV HO a/γ parametrization [51], which we transformed from the DIS to the MS factorization scheme. These photon PDFs have been tested profoundly at HERA and the Large Electron-Positron (LEP) collider at CERN and are very robust, in particular at high x (dominated by the pQCD photon-quark splitting), which is correlated with the low-x gluons γ A and sea quarks in Pb that present one of the points of interest of the present study. For nuclear PDFs f (x , µ ), b/B A we employed the nCTEQ15 parametrization [34]. The photon flux f (y) produced by a relativistic point-like charge γ/A Z is given by the standard expression 2 2 2α Z 1 ζ e.m. 2 2 f (y) = ζK (ζ)K (ζ) − (K (ζ) − K (ζ)) , (2) γ/A 0 1 1 0 π y 2 where α is the fine-structure constant; K are modified Bessel functions of the second kind; ζ = ym b with m e.m. 0,1 p min p being the proton mass and b the minimal distance between two nuclei. For Pb-Pb UPCs, Eq. (2) with b = 14.2 min min fm reproduces very well the photon flux calculated taking into account the nuclear form factor and the suppression of strong interactions at impact parameters b < b , see the discussion in [52]. min The NLO calculation of the dijet photoproduction cross section using Eq. (1) is numerically implemented in an NLO parton-level Monte Carlo [45, 47–49], which has been successfully tested in many different environments (HERA, LEP, Tevatron). It implements the anti-k algorithm (but we have at most two partons in the jet) and all the kinematic conditions and cuts used in the ATLAS analysis [38] that are explicitly explained in the following section. Hadronization corrections and underlying event (UE) subtractions are not part of our analysis, but they are expected to be performed with PYTHIA simulations by the experiment once the data are final (as has been done at HERA). III. PREDICTIONS FOR DIJET PHOTOPRODUCTION IN PB-PB COLLISIONS AT THE LHC The main goal of the present paper is the first NLO QCD calculation of the cross section of inclusive dijet photo- production in Pb-Pb UPCs and the conclusion whether it can describe the results of the ATLAS measurement [38]. The ATLAS analysis was performed using the following conditions and selection criteria: • the anti-k algorithm with the jet radius R = 0.4; • the leading jet has p > 20 GeV, while the other jets have a different cut on p > 15 GeV as required [53], T,1 T,i6=1 which corresponds to 35 < H < 400 GeV, where H = p ; T T T,i • all jets have rapidities |η | < 4.4; • the combined mass of all reconstructed jets is 35 < m < 400 GeV; jets −4 • the parton momentum fraction on the photon side z = yx , 10 < z < 0.05; γ γ γ −4 • the parton momentum fraction on the nucleus side x , 5 × 10 < x < 1. A A The ATLAS results are presented as distributions in terms of the total jet transverse momentum H = p and T T,i the photon z and nucleus x light-cone momentum fractions γ A m m jets jets y −y jets jets z = √ e , x = √ e , (3) γ A s s NN NN 4 Pb-Pb, 5.02 TeV 0.0023 < x <0.0049 -2 0.0049 < x < 0.01 (×10 ) nCTEQ15 10 -4 0.01 < x < 0.022 (×10 ) -6 0.022 < x < 0.048 (×10 ) -8 0.048 < x < 0.1 (×10 ) -10 0.1 < x < 0.22 (×10 ) -12 0.22 < x < 0.47 (×10 ) ATLAS (prel., not unfold.) -2 -4 -6 -8 -10 -12 -14 -16 50 100 150 200 250 300 H (GeV) FIG. 2: NLO QCD predictions for the cross section of dijet photoproduction in Pb-Pb UPCs at s = 5.02 TeV in the NN ATLAS kinematics as a function of H for different bins of x . The central values and the corresponding shaded uncertainty T A bands are obtained using nCTEQ15 nPDFs. The crosses are the ATLAS data points that we extracted from [38]. where   1/2 2 2 P X X 1 E + p i z,i   m = E − ~p , y = ln . (4) jets i i jets 2 E − p i z,i i i In Eqs. (4), the index i runs over all measured jets; E and ~p denote the jet energy and momentum, respectively. i i Note that at LO, the kinematics of 2 → 2 parton scattering and the momentum fractions z and x can be exactly γ A reconstructed from the dijet measurement. At NLO, Eqs. (3) serve as hadron-level estimators of the momentum fractions entering Eq. (1); for brevity, we use the same notations in Eqs. (1) and (4). Figures 2, 3, 4, and 5 show our results for the cross section of dijet photoproduction in Pb-Pb UPCs in the ATLAS kinematics (see above) as a function of H , x , and z for different bins of these variables. They correspond to Figs. T A γ 12-15 of Ref. [38]. In each bin, our predictions are obtained using the central fit of nCTEQ15 nPDFs [34]. The shaded bands quantify the uncertainty of our results Δσ due to the uncertainty of nCTEQ15 nPDFs. It is calculated by dσ/dH dx (μb/GeV) T A 5 Pb-Pb, 5.02 TeV nCTEQ15 -2 -4 -6 -8 42 < H < 50 GeV -1 50 < H < 59 GeV (×10 ) -2 59 < H < 70 GeV (×10 ) -3 70 < H < 84 GeV (×10 ) -4 84 < H < 100 GeV (×10 ) -5 -10 100 < H < 119 GeV (×10 ) 10 T -6 119 < H < 141 GeV (×10 ) -7 141 < H < 168 GeV (×10 ) -8 168 < H < 200 GeV (×10 ) ATLAS (prel.,not unfol.) -12 -3 -2 -1 0 10 10 10 10 FIG. 3: NLO QCD predictions for the cross section of dijet photoproduction in Pb-Pb UPCs at s = 5.02 TeV in the NN ATLAS kinematics as a function of x for different bins of H . The crosses are the ATLAS data points that we extracted from A T [38]. adding in quadrature the individual uncertainties corresponding to each of 32 error sets Δσ = (σ(f ) − σ(f )) , (5) k k+1 k=1, odd where σ(f ) is the cross section calculated using the f nCTEQ15 error nPDFs. k k A comparison of our results shown in Figs. 2, 3, 4, and 5 with Figs. 12-15 of Ref. [38] demonstrates that our calculations describe well the corresponding distributions. To illustrate this point, in Figs. 2 and 3, which present the phenomenologically important distributions in H and x , respectively, we also explicitly show by crosses the T A ATLAS data points, which we extracted from [38] using the WebPlotDigitizer tool [54]. One can readily see from these figures that the results of our calculations describe both the shape and normalization of the data rather well. The description of the remaining two distributions is also adequate. Note that the ATLAS data is preliminary and has not been corrected (unfolded) for the detector response. dσ/dH dx (μb/GeV) T A 6 Pb-Pb, 5.02 TeV nCTEQ15 -1 -2 -3 -4 -5 -6 42 < H < 50 GeV -7 -1 50 < H < 59 GeV (×10 ) -2 59 < H < 70 GeV (×10 ) -3 70 < H < 84 GeV (×10 ) -8 10 -4 84 < H < 100 GeV (×10 ) -5 100 < H < 119 GeV (×10 ) -6 -9 119 < H < 141 GeV (×10 ) 10 T -7 141 < H < 168 GeV (×10 ) -8 168 < H < 200 GeV (×10 ) -10 -4 -3 -2 -1 10 10 10 10 FIG. 4: NLO QCD predictions for the cross section of dijet photoproduction in Pb-Pb UPCs at s = 5.02 TeV in the NN ATLAS kinematics as a function of z for different bins of H . γ T To assess the impact of measurements of the inclusive dijet photoproduction cross section on nPDFs, we focus on the x distribution. Our results are shown in Figs. 6 and 7. In Fig. 6, we show the ratio of the cross section calculated using nCTEQ15 nPDFs in lead to the one calculated in the impulse approximation (IA), where nuclear PDFs are assumed not to include any nuclear modifications and are given by the weighted sum of free proton and IA neutron PDFs, f = Zf + (A − Z)f . The panels in this figure corresponds to nine bins in H presented in b/p b/n b/A Fig. 3 (the numerator of the presented ratio is given by the curves in Fig. 3). One can see that the cross section 2 2 ratio as a function of x behaves similarly to the ratio R = f (x, µ )/[Af (x, µ )] of the nuclear and nucleon A g g/A g/N gluon distributions. It dips below unity for x < 0.01 due to nuclear shadowing and then becomes enhanced around x = 0.1 due to the assumed gluon antishadowing. For x > 0.3, the cross section ratio shows again a suppression A A due to the EMC effect encoded in the nPDFs. While the scaling violations (the H dependence) of the shown ratios are difficult to see, they seem to be positive at small x ∼ 0.01 and negative at large x, as they should be, cf. [34, 35]. Note that in spite of large values of the resolution scale probed in the considered kinematics, µ > O(20) GeV, one can see that one is still sensitive to nuclear modifications of the PDFs at the 10 − 20% level for the central value of our predictions. One should also note that the uncertainty due to nPDFs, which is given by the shaded bands, is dσ/dH dz (μb/GeV) T γ 7 0.0002 < z < 0.0003 Pb-Pb, 5.02 TeV -2 0.0003 < z < 0.0006 (×10 ) -4 nCTEQ15 0.0006 < z < 0.0012 (×10 ) -6 0.0012 < z < 0.0022 (×10 ) -8 0.0022 < z < 0.0042 (×10 ) 10 -10 0.0042 < z < 0.0077 (×10 ) -12 0.0077 < z < 0.0144 (×10 ) -14 0.0144 < z < 0.0269 (×10 ) -2 -4 -6 -8 -10 -12 -14 -16 -3 -2 -1 0 10 10 10 10 FIG. 5: NLO QCD predictions for the cross section of dijet photoproduction in Pb-Pb UPCs at s = 5.02 TeV in the NN ATLAS kinematics as a function of x for different bins of z . A γ significant and comparable to the size of the discussed nuclear modifications. This can be viewed as an opportunity to reduce uncertainties of nPDFs using data on cross section of inclusive dijet photoproduction in nuclei in global QCD fits of nPDFs. In Fig. 7, we show our predictions for the dijet cross section as a function of x integrated over H and z . The A T γ top panel presents separately the resolved (green, dot-dashed) and the direct (blue, dashed) photon contributions to the cross section as well as their sum (red, solid). As can be expected, because of the correlation between x and z , see Eq. (3), the resolved photon contribution dominates for x > 0.01. We find that for small x < 0.01, γ A A the two contributions are comparable with the direct contribution being somewhat larger. While this behavior is qualitatively similar to the results of the LO analysis in the framework of PYTHIA 8 with EPPS16 nPDFs [55], the relative contribution of the resolved photon term is larger at NLO, but this statement depends of course on the choice of the photon factorization scheme and scale. The middle panel of Fig. 7 presents the ratio to the impulse approximation. Similarly to the trend already observed in Fig. 6 and discussed above, this ratio as a function of x behaves similarly to R . This behavior is similar to the A g one observed in the case of dijet photoproduction in the kinematics of an Electron-Ion Collider (EIC) [56]. dσ/dz dx (μb) γ A 8 1.3 1.3 42 < H < 50 GeV T 100 < H < 119 GeV 1.2 1.2 1.1 1.1 1.0 1.0 0.9 0.9 0.8 0.8 0.7 0.7 0.6 0.6 1.3 1.3 50 < H < 59 GeV 119 < H < 141 GeV 1.2 1.2 T T 1.1 1.1 1.0 1.0 0.9 0.9 0.8 0.8 0.7 0.7 0.6 0.6 1.3 1.3 59 < H < 70 GeV 141 < H < 168 GeV 1.2 1.2 T T 1.1 1.1 1.0 1.0 0.9 0.9 0.8 0.8 0.7 0.7 0.6 0.6 1.3 1.3 168 < H < 200 GeV 70 < H < 84 GeV 1.2 1.2 T 1.1 1.1 1.0 0.9 1.0 0.8 0.9 0.7 0.6 0.8 -3 -2 -1 0 10 10 10 10 0.7 0.6 1.3 84 < H < 100 GeV 1.2 1.1 1.0 0.9 0.8 0.7 0.6 -3 -2 -1 0 10 10 10 10 FIG. 6: NLO QCD predictions for the ratio of the cross section of dijet photoproduction to that calculated in IA in Pb-Pb UPCs at s = 5.02 TeV in the ATLAS kinematics as a function of x for different H bins. The shaded bands give the NN A T uncertainty of nCTEQ15 nPDFs. Note that in the future and if/when experimental data become available, to study nuclear modifications of nPDFs one can directly form the ratio of dijet cross sections measured in Pb-Pb and proton-proton (pp) UPCs as a function of x . While the systematics are highly correlated between bins in x , the information on nPDFs is in the shape of A A the cross section ratio, see the middle panel of Fig. 7 and its discussion above. Also, while the central Pb-Pb and pp collisions are very different, Pb-Pb and pp UPCs have comparable multiplicities. Thus, one can expect that the systematic uncertainties largely cancel in the nucleus-to-proton cross section ratio. Finally, the bottom panel of Fig. 7 presents the ratio of the dijet cross section calculated using nCTEQ15 nPDFs to the one calculated with the central value of EPPS16 nPDFs. The shaded band quantifies the uncertainty of the nCTEQ15 fit. One can see from the panel that the two parameterizations of nPDFs give similar predictions, which differ by at most 5% for all but one values of x . We have also explicitly checked that the use of nPDFs calculated in the model of leading twist nuclear shadowing [32] gives similarly close predictions for the dijet photoproduction cross section. In our calculations, following the standard prescription for setting the hard scale in QCD calculations, we used nCTEQ15/nCTEQ15(IA)nCTEQ15/nCTEQ15(IA) nCTEQ15/nCTEQ15(IA) nCTEQ15/nCTEQ15(IA) nCTEQ15/nCTEQ15(IA) 9 Pb-Pb, 5.02 TeV nCTEQ15 resolved direct -3 -2 -1 0 10 10 10 10 1.3 1.2 1.1 1.0 0.9 0.8 0.7 0.6 -3 -2 -1 0 10 10 10 10 1.3 1.2 1.1 1.0 0.9 0.8 0.7 0.6 -3 -2 -1 0 10 10 10 10 FIG. 7: NLO QCD predictions for the cross section of dijet photoproduction in Pb-Pb UPCs at s = 5.02 TeV in the NN ATLAS kinematics as a function of xA. Top: The resolved (green, dot-dashed) and direct (blue, dashed) photon contributions and their sum (red, solid). Middle: The ratio to the impulse approximation. Bottom: The ratio of cross sections calculated using the nCTEQ15 and EPPS16 nPDFs. The shaded bands show the uncertainty of nCTEQ15 nPDFs. µ = 2E in Eq. (1). In detail, we performed calculations using µ = (E /4, E /2, E , 2 E , 4 E ) both at T,1 T,1 T,1 T,1 T,1 T,1 NLO and LO and found that (i) the integrated cross section of inclusive dijet photoproduction at NLO as a function of µ is approximately constant is the vicinity of µ = 2E , (ii) while the NLO cross section slightly increases with T,1 an increase of µ up to 2E and then starts to decrease again, the LO cross section steeply decreases monotonically, T,1 and (iii) the values of the two cross sections are close around µ = 2E . Therefore, µ = 2E in Eq. (1) corresponds T,1 T,1 to the choice, which is most numerically stable against higher-order corrections. In this work, we used the framework of collinear factorization and NLO perturbative QCD to examine the sensitivity of the dijet photoproduction cross section to nuclear modifications of PDFs. Alternatively, one can use this process to look for signs of the BFKL and gluon saturation dynamics in the high-energy (k ) factorization approach [57]. dσ/dx (nb) nCTEQ15/EPPS16 nCTEQ15/nCTEQ15(IA) A 10 IV. CONCLUSIONS In this work, we calculated the cross section of inclusive dijet photoproduction in Pb-Pb UPCs at the LHC using NLO perturbative QCD and nCTEQ15 nPDFs. We showed that our approach provides a good description of various cross section distributions measured by the ATLAS collaboration. We found that the calculated dijet photoproduction cross section is sensitive to nuclear modifications of the PDFs. In particular, as a function of the nucleus momentum fraction x , the ratio of the cross sections calculated with nPDFs and in the impulse approximation behaves similarly to R for given µ and deviates from unity by 10 − 20% for the central nCTEQ15 fit. The calculations using EPPS16 nPDFs and predictions of the leading twist nuclear shadowing model give similar results. Therefore, inclusive dijet photoproduction on nuclei has the potential to reduce uncertainties in determination of nPDFs, which are comparable to the magnitude of the calculated nuclear modifications of the dijet photoproduction cross section. Our present analysis is a step in this direction. Acknowledgments VG would like to thank A. Angerami, I. Helenius, K. Kovarik, H. Paukkunen, and M. Strikman for useful discussions and the Institut fu¨r Theoretische Physik, Westfa¨lische Wilhelms-Universit¨at Mu¨nster for hospitality. VG’s research is supported in part by RFBR, research project 17-52-12070. The authors gratefully acknowledge financial support of DFG through the grant KL 1266/9-1 within the framework of the joint German-Russian project “New constraints on nuclear parton distribution functions at small x from dijet production in γA collisions at the LHC”. [1] A. J. Baltz et al., Phys. Rept. 458, 1 (2008) [arXiv:0706.3356 [nucl-ex]]. [2] S. R. Klein, Nucl. Phys. A 967, 249 (2017) [arXiv:1704.04715 [nucl-ex]]. [3] S. R. Klein, Phys. Rev. C 97, 054903 (2018) [arXiv:1801.04320 [nucl-th]]. [4] V. P. Gonc ¸alves, M. M. Jaime, D. E. Martins and M. S. Rangel, Phys. Rev. D 97, 074024 (2018) [arXiv:1802.07339 [hep-ph]]. [5] D. d’Enterria and G. G. da Silveira, Phys. Rev. Lett. 111, 080405 (2013) [Erratum: Phys. Rev. Lett. 116, 129901 (2016)] [arXiv:1305.7142 [hep-ph]]. [6] S. Fichet, G. von Gersdorff, B. Lenzi, C. Royon and M. Saimpert, JHEP 1502, 165 (2015) [arXiv:1411.6629 [hep-ph]]. [7] M. K lusek-Gawenda, P. Lebiedowicz and A. Szczurek, Phys. Rev. C 93, 044907 (2016) [arXiv:1601.07001 [nucl-th]]. [8] A. van Hameren, M. K lusek-Gawenda and A. Szczurek, Phys. Lett. B 776, 84 (2018) [arXiv:1708.07742 [hep-ph]]. [9] R. Aaij et al. [LHCb Collaboration], J. Phys. G 40, 045001 (2013) [arXiv:1301.7084 [hep-ex]]. [10] R. Aaij et al. [LHCb Collaboration], J. Phys. G 41, 055002 (2014) [arXiv:1401.3288 [hep-ex]]. [11] B. B. Abelev et al. [ALICE Collaboration], Phys. Rev. Lett. 113, 232504 (2014) [arXiv:1406.7819 [nucl-ex]]. [12] E. Abbas et al. [ALICE Collaboration], Eur. Phys. J. C 73, 2617 (2013) [arXiv:1305.1467 [nucl-ex]]. [13] B. Abelev et al. [ALICE Collaboration], Phys. Lett. B 718, 1273 (2013) [arXiv:1209.3715 [nucl-ex]]. [14] J. Adam et al. [ALICE Collaboration], Phys. Lett. B 751, 358 (2015) [arXiv:1508.05076 [nucl-ex]]. [15] V. Khachatryan et al. [CMS Collaboration], Phys. Lett. B 772, 489 (2017) [arXiv:1605.06966 [nucl-ex]]. [16] R. Aaij et al. [LHCb Collaboration], JHEP 1509, 084 (2015) [arXiv:1505.08139 [hep-ex]]. [17] R. Chudasama et al. [CMS Collaboration], PoS ICPAQGP 2015, 042 (2017) [arXiv:1607.00786 [hep-ex]]. [18] S. P. Jones, A. D. Martin, M. G. Ryskin and T. Teubner, JHEP 1311, 085 (2013) [arXiv:1307.7099 [hep-ph]]. [19] V. Guzey and M. Zhalov, JHEP 1310, 207 (2013) [arXiv:1307.4526 [hep-ph]]. [20] A. Adeluyi and C. A. Bertulani, Phys. Rev. C 85, 044904 (2012) [arXiv:1201.0146 [nucl-th]]. [21] V. Guzey, E. Kryshen, M. Strikman and M. Zhalov, Phys. Lett. B 726, 290 (2013) [arXiv:1305.1724 [hep-ph]]. [22] T. Lappi and H. M¨ antysaari, Phys. Rev. C 87, 032201 (2013) [arXiv:1301.4095 [hep-ph]]. [23] V. P. Goncalves, B. D. Moreira and F. S. Navarra, Phys. Rev. C 90, 015203 (2014) [arXiv:1405.6977 [hep-ph]]. [24] H. M¨ antysaari and B. Schenke, Phys. Lett. B 772, 832 (2017) [arXiv:1703.09256 [hep-ph]]. [25] C. Adler et al. [STAR Collaboration], Phys. Rev. Lett. 89, 272302 (2002) [nucl-ex/0206004]. [26] B. I. Abelev et al. [STAR Collaboration], Phys. Rev. C 77, 034910 (2008) [arXiv:0712.3320 [nucl-ex]]. [27] G. Agakishiev et al. [STAR Collaboration], Phys. Rev. C 85, 014910 (2012) [arXiv:1107.4630 [nucl-ex]]. [28] J. Adam et al. [ALICE Collaboration], JHEP 1509, 095 (2015) [arXiv:1503.09177 [nucl-ex]]. [29] V. Rebyakova, M. Strikman and M. Zhalov, Phys. Lett. B 710, 647 (2012) [arXiv:1109.0737 [hep-ph]]. [30] L. Frankfurt, V. Guzey, M. Strikman and M. Zhalov, Phys. Lett. B 752, 51 (2016) [arXiv:1506.07150 [hep-ph]]. [31] M. G. Ryskin, Z. Phys. C 57, 89 (1993). [32] L. Frankfurt, V. Guzey and M. Strikman, Phys. Rept. 512, 255 (2012) [arXiv:1106.2091 [hep-ph]]. [33] K. J. Eskola, H. Paukkunen and C. A. Salgado, JHEP 0904, 065 (2009) [arXiv:0902.4154 [hep-ph]]. [34] K. Kovarik et al., Phys. Rev. D 93, 085037 (2016) [arXiv:1509.00792 [hep-ph]]. 11 [35] K. J. Eskola, P. Paakkinen, H. Paukkunen and C. A. Salgado, Eur. Phys. J. C 77, 163 (2017) [arXiv:1612.05741 [hep-ph]]. [36] D. Y. Ivanov, A. Sch¨ afer, L. Szymanowski and G. Krasnikov, Eur. Phys. J. C 34, 297 (2004) [Erratum: Eur. Phys. J. C 75, 75 (2015)] [hep-ph/0401131]. [37] S. P. Jones, A. D. Martin, M. G. Ryskin and T. Teubner, J. Phys. G 43, 035002 (2016) [arXiv:1507.06942 [hep-ph]]. [38] The ATLAS collaboration, ”Photo-nuclear dijet production in ultra-peripheral Pb+Pb collisions”, ATLAS-CONF-2017- 011, February 2017. [39] M. Strikman, R. Vogt and S. N. White, Phys. Rev. Lett. 96, 082001 (2006) [hep-ph/0508296]. [40] V. Guzey and M. Klasen, JHEP 1604, 158 (2016) [arXiv:1603.06055 [hep-ph]]. [41] E. Basso, V. P. Goncalves, A. K. Kohara and M. S. Rangel, Eur. Phys. J. C 77, no.9, 600 (2017) [arXiv:1705.08834 [hep-ph]]. [42] C. A. Salgado et al., J. Phys. G 39, 015010 (2012) [arXiv:1105.3919 [hep-ph]]. [43] A. Accardi et al., Eur. Phys. J. A 52, 268 (2016) [arXiv:1212.1701 [nucl-ex]]. [44] J. L. Abelleira Fernandez et al. [LHeC Study Group], J. Phys. G 39, 075001 (2012) [arXiv:1206.2913 [physics.acc-ph]]. [45] M. Klasen, Rev. Mod. Phys. 74, 1221 (2002) [hep-ph/0206169]. [46] C. A. Bertulani, S. R. Klein and J. Nystrand, Ann. Rev. Nucl. Part. Sci. 55, 271 (2005) [nucl-ex/0502005]. [47] M. Klasen and G. Kramer, Z. Phys. C 72, 107 (1996) [hep-ph/9511405]. [48] M. Klasen and G. Kramer, Z. Phys. C 76, 67 (1997) [hep-ph/9611450]. [49] M. Klasen, T. Kleinwort and G. Kramer, Eur. Phys. J. direct 1, 1 (1998) [hep-ph/9712256]. [50] M. Klasen and G. Kramer, Eur. Phys. J. C 71, 1774 (2011) [arXiv:1104.0095 [hep-ph]]. [51] M. Glu ¨ck, E. Reya and A. Vogt, Phys. Rev. D 46, 1973 (1992). [52] J. Nystrand, Nucl. Phys. A 752, 470 (2005) [hep-ph/0412096]. [53] M. Klasen and G. Kramer, Phys. Lett. B 366, 385 (1996) [hep-ph/9508337]. [54] http://arohatgi.info/WebPlotDigitizer [55] I. Helenius, arXiv:1806.07326 [hep-ph]. [56] M. Klasen and K. Kovarik, Phys. Rev. D 97, no.11, 114013 (2018) [arXiv:1803.10985 [hep-ph]]. [57] P. Kotko, K. Kutak, S. Sapeta, A. M. Stasto and M. Strikman, Eur. Phys. J. C 77, no.5, 353 (2017 [arXiv:1702.03063 [hep-ph]].

Journal

High Energy Physics - Phenomenology – arXiv (Cornell University)

Published: Nov 26, 2018

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