Meson-baryon scattering to one-loop order in heavy baryon chiral perturbation theory
AbstractWe calculate the T-matrices of pseudoscalar meson octet-baryon scattering to one-loop order in SU(3) heavy baryon chiral perturbation theory. The pertinent combinations of low-energy constants are determined by fitting to phase shifts of πN and KN scattering and the corresponding data. By using these low-energy constants, we obtain the strong phase shift difference of πΛ scattering at the Ξ mass, δP-δS=(8.8±0.2) degrees, in agreement with experimental results. We find that the phase shifts in the S01(πΣ), S01(KΞ), S01(K¯N), and S11(K¯Σ) waves are so strong that resonances may be generated dynamically in all these channels. We also predict the scattering lengths and make comparisons with the results obtained from the threshold T-matrices in heavy baryon chiral perturbation theory and the method of covariant infrared regularization. The issue of convergence is also discussed in detail.