Pion-nucleon elastic scattering amplitude within covariant baryon chiral perturbation theory up to O(p4) level

The O(p4) calculation on pion-nucleon elastic scattering amplitude in EOMS scheme within covariant baryon chiral perturbation theory is reviewed. Numerical fits to partial wave amplitudes up to s = 1.13GeV and 1.20GeV are performed and the results are compared with previous studies.