Non-perturbative chiral approach to K−p → γ Y reactions

Abstract

A recently developed non-perturbative chiral approach to describe the S = −1 meson-baryon reactions has been extended to investigate the near threshold K − p → γΛ,γΣ 0 reactions. With the parameters governed by chiral SU(3) symmetry, we show that the predicted branching ratios Γ K − p→γΛ /Γ K − p→ all and Γ K − p→γΣ 0 /Γ K − p→ all are close to the experimental values. The coupling with the η channels, which was shown to be important in the S = −1 meson-baryon reactions, is also found to be significant here. Our results are consistent with the interpretation of the Λ(1405) as a quasi-bound meson-baryon state as found in other similar chiral approaches.