%0 Journal Article
%T New insights on low energy pi N scattering amplitudes: comprehensive analyses at O (p(3)) level
%A Wang, Y. F.
%A Yao, D. L.
%A Zheng, H. Q.
%J Chinese Physics C
%D 2019
%V 43
%N 6
%I Iop Publishing Ltd
%@ 1674-1137
%G English
%F Wang_etal2019
%O WOS:000468501700013
%O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=4020), last updated on Wed, 05 Jun 2019 11:00:29 +0000
%X A production representation of partial-wave S matrix is utilized to construct low-energy elastic pion-nucleon scattering amplitudes from cuts and poles on complex Riemann sheets. Among them, the contribution of left-hand cuts is estimated using the O (p(3)) results obtained in covariant baryon chiral perturbation theory within the extendedon-nass-shell scheme. By fitting to data on partial-wave phase shifts, it is indicated that the existences of hidden poles in S-11 and P-11 channels, as conjectured in our previous paper [Eur. Phys. J. C, 78(7): 543 (2018)], are firmly established. Specifically, the pole mass of the S-11 hidden resonance is determined to be (895 +/- 81)-(164 +/- 23)i MeV, whereas, the virtual pole in the P-11 channel locates at (966 +/- 18) MeV. It is found that analyses at the O (p(3)) level improves significantly the fit quality, comparing with the previous O (p(2)) one. Quantitative studies with cautious physical discussions are also conducted for the other S- and P-wave channels.
%K dispersion relations
%K pion-nucleon scattering
%K chiral perturbation theory
%R 10.1088/1674-1137/43/6/064110
%U https://arxiv.org/abs/1811.09748
%U https://doi.org/10.1088/1674-1137/43/6/064110
%P 064110-22pp