Partial-wave analysis of $K^+$ nucleon scattering

TL;DR

This paper conducts a detailed partial-wave analysis of K+ nucleon scattering data up to 1.5 GeV/c, highlighting the importance of threshold behavior and suggesting possible pentaquark production.

Contribution

It provides a new partial-wave analysis with improved treatment of threshold effects and challenges previous claims about the T=0 scattering length.

Findings

T=0 scattering length is non-zero

T=0 phase shifts for ℓ>0 align with a spin-orbit potential

Possible evidence for T=0 pentaquark with D5/2+

Abstract

We have performed a partial-wave analysis of K$^+$-nucleon scattering in the momentum range from 0 to 1.5 GeV/c addressing the uncertainties of the results and comparing them with several previous analyses. It is found that the treatment of the reaction threshold behavior is particularly important. We find a T=0 scattering length which is not consistent with zero, as has been claimed by other analyses. The T=0 phase shifts for $\ell>0$ are consistent with a pure spin-orbit potential. Some indications for the production of a T=0 pentaquark with spin-parity D5/2+ are discussed.