Strangeness Photoproduction at the BGO-OD experiment

Abstract

The BGO-OD experiment at the ELSA accelerator facility uses an energy tagged bremsstrahlung photon beam to investigate the excitation structure of the nucleon. The setup consists of a highly segmented BGO calorimeter surrounding the target, with a particle tracking magnetic spectrometer at forward angles. BGO-OD is ideal for investigating low momentum transfer processes due to the acceptance and high momentum resolution at forward angles. In particular, this enables the investigation of strangeness photoproduction where t-channel exchange mechanisms play an important role. This also allows access to low momentum exchange kinematics where extended, molecular structure may manifest in reaction mechanisms. First key results at low t indicate a cusp-like structure in K+Σ0 photoproduction at W = 1900 MeV, line shapes and differential cross sections for K+Λ(1405)→ K+Σ0π0, and a peak structure in K0SΣ0 photoproduction. The peak in the K0SΣ0 channel appears consistent with meson-baryon generated states, where equivalent models have been used to describe the PC pentaquark candidates in the heavy charmed quark sector.

Light Baryon Spectroscopy

“…In addition, this data helps to constrain the t-channel K and K * exchange at forward angles and low momentum transfer. More data regarding strangeness photoproduction can be expected from the BGOOD facility in the future [137,328,329,330].…”