Differential Photoproduction Cross Sections of the Sigma0(1385), Lambda(1405), and Lambda(1520)

TL;DR

This paper measures the exclusive photoproduction cross sections of Sigma(1385), Lambda(1405), and Lambda(1520) hyperons using CLAS, revealing differences in decay channels and testing theoretical models at energies up to 2.85 GeV.

Contribution

First comprehensive measurement of these hyperons' photoproduction cross sections across a wide energy range, highlighting isospin interference effects.

Findings

Cross sections vary significantly across decay channels.

Models show wide accuracy variation.

Isospin interference affects Lambda(1405) decay channels.

Abstract

We report the exclusive photoproduction cross sections for the Sigma(1385), Lambda(1405), and Lambda(1520) in the reactions gamma + p -> K+ + Y* using the CLAS detector for energies from near the respective production thresholds up to a center-of-mass energy W of 2.85 GeV. The differential cross sections are integrated to give the total exclusive cross sections for each hyperon. Comparisons are made to current theoretical models based on the effective Lagrangian approach and fitted to previous data. The accuracy of these models is seen to vary widely. The cross sections for the Lambda(1405) region are strikingly different for the Sigma+pi-, Sigma0 pi0, and Sigma- pi+ decay channels, indicating the effect of isospin interference, especially at W values close to the threshold.