"The European Physical Journal C"

Abdallah, J.;Abreu, P.;Adam, W.;Adzic, P.;Albrecht, T.;Alemany-Fernandez, R.;Allmendinger, T.;Allport, P.P.;Amaldi, U.;Amapane, N.;Amato, S.;Anashkin, E.;Andreazza, A.;Andringa, S.;Anjos, N.;Antilogus, P.;Apel, W-D.;Arnoud, Y.;Ask, S.;Asman, B.;Augustin, J.E.;Augustinus, A.;Baillon, P.;Ballestrero, A.;Bambade, P.;Barbier, R.;Bardin, D.;Barker, G.J.;Baroncelli, A.;Battaglia, M.;Baubillier, M.;Becks, K-H.;Begalli, M.;Behrmann, A.;Ben-Haim, E.;Benekos, N.;Benvenuti, A.;Berat, C.;Berggren, M.;Bertrand, D.;Besancon, M.;Besson, N.;Bloch, D.;Blom, M.;Bluj, M.;Bonesini, M.;Boonekamp, M.;Booth, P.S.L.;Borisov, G.;Botner, O.;Bouquet, B.;Bowcock, T.J.V.;Boyko, I.;Bracko, M.;Brenner, R.;Brodet, E.;Bruckman, P.;Brunet, J.M.;Buschbeck, B.;Buschmann, P.;Calvi, M.;Camporesi, T.;Canale, V.;Carena, F.;Castro, N.;Cavallo, F.;Chapkin, M.;Charpentier, Ph.;Checchia, P.;Chierici, R.;Chliapnikov, P.;Chudoba, J.;Chung, S.U.;Cieslik, K.;Collins, P.;Contri, R.;Cosme, G.;Cossutti, F.;Costa, M.J.;Crennell, D.;Cuevas, J.;D’Hondt, J.;Silva, T. da;Silva, W. Da;Della Ricca, G.;De Angelis, A.;De Boer, W.;De Clercq, C.;De Lotto, B.;De Maria, N.;De Min, A.;de Paula, L.;Di Ciaccio, L.;Di Simone, A.;Doroba, K.;Drees, J.;Eigen, G.;Ekelof, T.;Ellert, M.;Elsing, M.;Santo, M.C. Espirito;Fanourakis, G.;Fassouliotis, D.;Feindt, M.;Fernandez, J.;Ferrer, A.;Ferro, F.;Flagmeyer, U.;Foeth, H.;Fokitis, E.;Fulda-Quenzer, F.;Fuster, J.;Gandelman, M.;Garcia, C.;Gavillet, Ph.;Gazis, E.;Gokieli, R.;Golob, B.;Gomez-Ceballos, G.;Goncalves, P.;Graziani, E.;Grosdidier, G.;Grzelak, K.;Guy, J.;Haag, C.;Hallgren, A.;Hamacher, K.;Hamilton, K.;Haug, S.;Hauler, F.;Hedberg, V.;Hennecke, M.;Hoffman, J.;Holmgren, S-O.;Holt, P.J.;Houlden, M.A.;Jackson, J.N.;Jarlskog, G.;Jarry, P.;Jeans, D.;Johansson, E.K.;Jonsson, P.;Joram, C.;Jungermann, L.;Kapusta, F.;Katsanevas, S.;Katsoufis, E.;Kernel, G.;Kersevan, B.P.;Kerzel, U.;King, B.T.;Kjaer, N.J.;Kluit, P.;Kokkinias, P.;Kourkoumelis, C.;Kouznetsov, O.;Krumstein, Z.;Kucharczyk, M.;Lamsa, J.;Leder, G.;Ledroit, F.;Leinonen, L.;Leitner, R.;Lemonne, J.;Lepeltier, V.;Lesiak, T.;Liebig, W.;Liko, D.;Lipniacka, A.;Lopes, J.H.;Lopez, J.M.;Loukas, D.;Lutz, P.;Lyons, L.;MacNaughton, J.;Malek, A.;Maltezos, S.;Mandl, F.;Marco, J.;Marco, R.;Marechal, B.;Margoni, M.;Marin, J-C.;Mariotti, C.;Markou, A.;Martinez-Rivero, C.;Masik, J.;Mastroyiannopoulos, N.;Matorras, F.;Matteuzzi, C.;Mazzucato, F.;Mazzucato, M.;Nulty, R. Mc;Meroni, C.;Migliore, E.;Mitaroff, W.;Mjoernmark, U.;Moa, T.;Moch, M.;Moenig, K.;Monge, R.;Montenegro, J.;Moraes, D.;Moreno, S.;Morettini, P.;Mueller, U.;Muenich, K.;Mulders, M.;Mundim, L.;Murray, W.;Muryn, B.;Myatt, G.;Myklebust, T.;Nassiakou, M.;Navarria, F.;Nawrocki, K.;Nicolaidou, R.;Nikolenko, M.;Oblakowska-Mucha, A.;Obraztsov, V.;Olshevski, A.;Onofre, A.;Orava, R.;Osterberg, K.;Ouraou, A.;Oyanguren, A.;Paganoni, M.;Paiano, S.;Palacios, J.P.;Palka, H.;Papadopoulou, Th.D.;Pape, L.;Parkes, C.;Parodi, F.;Parzefall, U.;Passeri, A.;Passon, O.;Peralta, L.;Perepelitsa, V.;Perrotta, A.;Petrolini, A.;Piedra, J.;Pieri, L.;Pierre, F.;Pimenta, M.;Piotto, E.;Podobnik, T.;Poireau, V.;Pol, M.E.;Polok, G.;Pozdniakov, V.;Pukhaeva, N.;Pullia, A.;Radojicic, D.;Rames, J.;Read, A.;Rebecchi, P.;Rehn, J.;Reid, D.;Reinhardt, R.;Renton, P.;Richard, F.;Ridky, J.;Rivero, M.;Rodriguez, D.;Romero, A.;Ronchese, P.;Roudeau, P.;Rovelli, T.;Ruhlmann-Kleider, V.;Ryabtchikov, D.;Sadovsky, A.;Salmi, L.;Salt, J.;Sander, C.;Savoy-Navarro, A.;Schwickerath, U.;Sekulin, R.;Siebel, M.;Sisakian, A.;Smadja, G.;Smirnova, O.;Sokolov, A.;Sopczak, A.;Sosnowski, R.;Spassov, T.;Stanitzki, M.;Stocchi, A.;Strauss, J.;Stugu, B.;Szczekowski, M.;Szeptycka, M.;Szumlak, T.;Tabarelli, T.;Tegenfeldt, F.;Timmermans, J.;Tkatchev, L.;Tobin, M.;Todorovova, S.;Tome, B.;Tonazzo, A.;Tortosa, P.;Travnicek, P.;Treille, D.;Tristram, G.;Trochimczuk, M.;Troncon, C.;Turluer, M-L.;Tyapkin, I.A.;Tyapkin, P.;Tzamarias, S.;Uvarov, V.;Valenti, G.;Van Dam, P.;Van Eldik, J.;Van Lysebetten, A.;van Remortel, N.;Van Vulpen, I.;Vegni, G.;Veloso, F.;Venus, W.;Verdier, P.;Verzi, V.;Vilanova, D.;Vitale, L.;Vrba, V.;Wahlen, H.;Washbrook, A.J.;Weiser, C.;Wicke, D.;Wickens, J.;Wilkinson, G.;Winter, M.;Witek, M.;Yushchenko, O.;Zalewska, A.;Zalewski, P.;Zavrtanik, D.;Zhuravlov, V.;Zimin, N.I.;Zintchenko, A.;Zupan, M.

doi: 10.1140/epjc/s10052-008-0528-3pmid: N/A

Abstract A determination of the single W spin density matrix (SDM) elements in the reaction e+e-→W+W-→lνqq̄(l=e/μ) is reported at centre-of-mass energies between 189 and 209 GeV. The data sample used corresponds to an integrated luminosity of 520 pb-1 taken by DELPHI between 1998 and 2000. The single W SDM elements, ρττ’ W± (τ,τ’=± 1 or 0), are determined as a function of the W- production angle with respect to the e- beam direction and are obtained from measurements of the W decay products by the application of suitable projection operators, Λττ’, which assume the V-A coupling of the W-boson to fermions. The measured SDM elements are used to obtain the fraction of longitudinally polarised Ws, with the result: \(\frac{\sigma_{\text{L}}}{\sigma_{{\text{tot}}}} = 24.9 \pm4.5({\text{stat}}) \pm2.2({\text{syst}})\%\) at a mean energy of 198 GeV. The SDM elements are also used to determine the triple gauge couplings Δg1 Z,Δκγ,λγ and g4 Z, \(\tilde{\kappa}_{Z}\) and \(\tilde{\lambda}_{Z}\). For the CP-violating couplings the results of single parameter fits are: \(g_4^{{Z}} = -0.39^{+0.19}_{-0.20}\) \(\tilde{\kappa}_{{Z}} = -0.09^{+0.08}_{-0.05}\) \(\tilde{\lambda}_{{Z}} = -0.08\pm0.07 .\) The errors are a combination of statistical and systematic errors. All results are consistent with the Standard Model.

Beddall, A.;Beddall, A.

doi: 10.1140/epjc/s10052-008-0539-0pmid: N/A

Abstract The ratio \(\mathcal{B}= \Gamma(\pi^0 \to{} e^+ e^- \gamma)/\Gamma(\pi^0 \to\gamma\gamma)\) is measured by comparing the production rates of the π0 in the two decay channels. The analysis is based on approximately four million hadronic decays of the Z boson recorded by the ALEPH detector in the years 1991 to 1995. The value of \(\mathcal{B}\) is determined to be \((1.140 \pm0.041)\%\). A recalculation of the Particle Data Group world average gives rise to a slightly improved error, and moves the world average closer to the theoretical value.

Aaron, F.D.;Aktas, A.;Alexa, C.;Andreev, V.;Antunovic, B.;Aplin, S.;Asmone, A.;Astvatsatourov, A.;Backovic, S.;Baghdasaryan, A.;Baranov, P.;Barrelet, E.;Bartel, W.;Baudrand, S.;Beckingham, M.;Begzsuren, K.;Behnke, O.;Behrendt, O.;Belousov, A.;Berger, N.;Bizot, J.C.;Boenig, M.-O.;

Aaron, F.D.;Aktas, A.;Alexa, C.;Andreev, V.;Antunovic, B.;Aplin, S.;Asmone, A.;Astvatsatourov, A.;Backovic, S.;Baghdasaryan, A.;Baranov, P.;Barrelet, E.;Bartel, W.;Baudrand, S.;Beckingham, M.;Begzsuren, K.;Behnke, O.;Behrendt, O.;Belousov, A.;Berger, N.;Bizot, J.C.;Boenig, M.-O.;

Batley, J.R.;Culling, A.J.;Kalmus, G.;Lazzeroni, C.;Munday, D.J.;Slater, M.W.;Wotton, S.A.;Arcidiacono, R.;Bocquet, G.;Cabibbo, N.;Ceccucci, A.;Cundy, D.;Falaleev, V.;Fidecaro, M.;Gatignon, L.;Gonidec, A.;Kubischta, W.;Norton, A.;Maier, A.;Patel, M.;Peters, A.;Balev, S.;

Abt, I.;Caldwell, A.;Kröninger, K.;Liu, J.;Liu, X.;Majorovits, B.

doi: 10.1140/epjc/s10052-008-0555-0pmid: N/A

Abstract Procedures developed to separate single- and multiple-site events in germanium detector are tested with specially selected event samples provided by an 18-fold segmented prototype germanium detector for phase II of the germanium detector array, GERDA. The single Compton scattering, i.e. single-site, events are tagged by coincidently detecting the scattered photon with a second detector positioned at a defined angle. A neural network is trained to separate such events from events which come from multi-site dominated samples. Identification efficiencies of ≈80% are achieved for both single- and multi-site events.

Şahin, B.;Şahin, İ.

doi: 10.1140/epjc/s10052-008-0543-4pmid: N/A

Abstract We investigate the potential of eγ collisions to probe anomalous Wtb couplings via the polarized single top quark production process e+γ→tb̄νē. We find 95% confidence level limits on the anomalous coupling parameters F2L and F2R with an integrated luminosity of 500 fb-1 and \(\sqrt{s}=0.5\), 1 and 1.5 TeV energies. The effects of top quark spin polarization on the anomalous Wtb couplings are discussed. It is shown that polarization leads to a considerable improvement in the sensitivity limits.

Machado, M.V.T.

doi: 10.1140/epjc/s10052-008-0526-5pmid: N/A

Abstract We present a study of heavy quarkonium production in hard diffractive processes by pomeron exchange for Tevatron and LHC energies. The numerical results are computed using a recent experimental determination of the diffractive parton density functions in the pomeron and these are corrected by unitarity corrections through the gap survival probability factor. We give predictions for single as well as central diffractive ratios. These processes are sensitive to the gluon content of the pomeron at small Bjorken variable x and may be particularly useful in studying small-xphysics. They may also be a good place to test the different available mechanisms for quarkonium production at hadron colliders.

Arbuzov, A.;Bardin, D.;Bondarenko, S.;Christova, P.;Kalinovskaya, L.;Nanava, G.;Sadykov, R.

doi: 10.1140/epjc/s10052-008-0531-8pmid: N/A

Abstract Radiative corrections to the neutral current Drell–Yan-like processes are considered. Complete one-loop electroweak corrections are calculated within the SANC system. Theoretical uncertainties are discussed. Numerical results are presented for typical conditions of LHC experiments.

Ananthanarayan, B.;Ramanan, S.

doi: 10.1140/epjc/s10052-008-0533-6pmid: N/A

Abstract The pionic contribution to the g-2 of the muon involves a certain integral over the modulus squared of Fπ(t), the electromagnetic form factor of the pion. We extend techniques that use cut-plane analyticity properties of Fπ(t) in order to account for present day estimates of the pionic contribution and experimental information at a finite number of points in the spacelike region. Using data from several experiments over a large kinematic range for |t|, we find bounds on the expansion coefficients of Fπ(t), sub-leading to the charge radius. The value of one of these coefficients in chiral perturbation theory respects these bounds. Furthermore, we present a sensitivity analysis to the inputs. A brief comparison with results in the literature that use observables other than the g-2 and timelike data is presented.