Radiative decays of the Sigma0(1385) and Lambda(1520) hyperons

TL;DR

This study reports the first observation of the radiative decay of Sigma0(1385) hyperons and measures the decay widths of Sigma0(1385) and Lambda(1520) hyperons using photon-induced reactions at Jefferson Lab.

Contribution

First observation of Sigma0(1385) radiative decay and measurement of decay widths, providing new experimental data for hyperon electromagnetic decays.

Findings

Measured Sigma0(1385) -> Lambda gamma partial width as 479+/-120 keV

Measured Lambda(1520) -> Lambda gamma partial width as 167+/-43 keV

Results exceed existing theoretical model predictions.

Abstract

The electromagnetic decays of the Sig0(1385) and Lambda(1520) hyperons were studied in photon-induced reactions gamma p -> K+ Lambda(1116)gamma in the CLAS detector at the Thomas Jefferson National Accelerator Facility. We report the first observation of the radiative decay of the Sig0(1385) and a measurement of the Lambda(1520) radiative decay width. For the Sig0(1385) -> Lambda(1116)gamma transition, we measured a partial width of 479+/-120(stat)+81-100(sys) keV, larger than all of the existing model predictions. For the Lambda(1520) -> Lambda(1116)gamma transition, we obtained a partial width of 167+/-43(stat)+26-12(sys) keV.