Near-threshold photoproduction of Lambda(1520) from protons and deuterons

Phys Rev Lett. 2009 Jul 3;103(1):012001. doi: 10.1103/PhysRevLett.103.012001. Epub 2009 Jul 1.

Abstract

Photoproduction of Lambda(1520) with liquid hydrogen and deuterium targets was examined at photon energies below 2.4 GeV in the SPring-8 LEPS experiment. For the first time, the differential cross sections were measured at low energies and with a deuterium target. A large asymmetry of the production cross sections from protons and neutrons was observed at backward K+/0 angles. This suggests the importance of the contact term, which coexists with t-channel K exchange under gauge invariance. This interpretation was compatible with the differential cross sections, decay asymmetry, and photon beam asymmetry measured in the production from protons at forward K+ angles.