PT Journal
AU Wang, YF
   Yao, DL
   Zheng, HQ
TI New insights on low energy pi N scattering amplitudes
SO European Physical Journal C
JI Eur. Phys. J. C
PY 2018
BP 543 - 18pp
VL 78
IS 7
DI 10.1140/epjc/s10052-018-6024-5
LA English
AB The S- and P- wave phase shifts of low-energy pion-nucleon scatterings are analysed using Peking University representation, in which they are decomposed into various terms contributing either from poles or branch cuts. We estimate the left-hand cut contributions with the help of tree-level perturbative amplitudes derived in relativistic baryon chiral perturbation theory up to O(p(2)). It is found that in S-11 and P-11 channels, contributions from known resonances and cuts are far from enough to saturate experimental phase shift data – strongly indicating contributions from low lying poles undiscovered before, and we fully explore possible physics behind. On the other side, no serious disagreements are observed in the other channels.
ER