Kaon photoproduction and electroproduction near threshold

TL;DR

This paper models the electromagnetic production of K^+Lambda and K^0Lambda near threshold, successfully describing experimental data and revealing a narrow resonance at 1650 MeV.

Contribution

It introduces an isobar model that accurately describes near-threshold kaon photoproduction and identifies a narrow P11 resonance at 1650 MeV.

Findings

Model fits experimental data well for K^+Lambda production.

Sizable effects of K^0 charge form factor on longitudinal cross section.

Identification of a narrow resonance at 1650 MeV with 5 MeV width.

Abstract

We analyze the electromagnetic production of K^+Lambda and K^0Lambda near their production thresholds by using isobar models. In the K^+Lambda channel we show that the model can nicely describe the available experimental data. In the K^0Lambda channel we demonstrate that the K^0 charge form factor has sizable effects on the longitudinal cross section. By extending the model up to W = 1730 MeV, we are able to observe the existence of the narrow P_{11} (J^p = 1/2^+) resonance in the kaon photoproduction process. It is found that the most convincing mass (width) of this resonance is 1650 MeV (5 MeV).