Photoproduction of Λ(1405) and Σ0(1385) on the proton at Eγ=1.5-2.4 GeV

Abstract

Differential cross sections for γp→K+Λ(1405) and γp→K+Σ0(1385) reactions have been measured in the photon energy range from 1.5 to 2.4 GeV and the angular range of 0.8 <1.0 for the K+ scattering angle in the center-of-mass system. This data is the first measurement of the Λ(1405) photoproduction cross section. The line shapes of Λ(1405) measured in Σ+π- and Σ-π+ decay modes were different with each other, indicating a strong interference of the isospin 0 and 1 terms of the Σπ scattering amplitudes. The ratios of Λ(1405) production to Σ0(1385) production were measured in two photon energy ranges: near the production threshold (1.5 <2.0 GeV) and far from it (2.0 <2.4 GeV). The observed ratio decreased in the higher photon energy region, which may suggest different production mechanisms and internal structures for these hyperon resonances. © 2008 The American Physical Society.