Further evidence for N(1900)P_{13} from photoproduction of hyperons

TL;DR

This paper provides additional evidence for the N(1900)P_{13} hyperon resonance through analysis of various photo- and pion-induced reactions, especially new polarization data, revealing different possible pole positions and explaining its elusive nature.

Contribution

It offers new experimental evidence supporting the existence and properties of the N(1900)P_{13} resonance, including its pole position and small elasticity, contributing to the understanding of hyperon spectroscopy.

Findings

Evidence supports the N(1900)P_{13} resonance with a pole at approximately 1915-i90 MeV.

The resonance has a small elasticity of 10% or less, explaining its elusive detection in certain scattering experiments.

The resonance is predicted by three-quark models but not by diquark-quark models.

Abstract

We report further evidence for $N(1900)P_{13}$ from an analysis of a large variety of photo- and pion-induced reactions, in particular from the new CLAS measurements of double polarization observables for photoproduction of hyperons. The data are consistent with two classes of solutions both requiring contributions from $N(1900)P_{13}$ but giving different $N(1900)P_{13}$ pole positions. $(M-i\Gamma/2) = (1915\pm50)-i(90\pm25)$ MeV covers both solutions. The small elasticity of 10% or less explains why it was difficult to observe the state in $\pi N$ elastic scattering. $N(1900)P_{13}$ is a 2-star resonance which is predicted by symmetric three-quark models. In diquark-quark models, the existence of the state is not expected.