Radiative production of the Λ(1405) resonance in K− collisions on protons and nuclei

We have carried out a theoretical study of the K−p→MBγ reaction with MB=K−p, K̄0n, π−Σ+, π+Σ−, π0Σ0,π0Λ, for K− lab. momenta between 200 and 500 MeV/c, using a chiral unitary approach for the strong K−p interaction with its coupled channels. The Λ(1405) resonance, which is generated dynamically in this approach, shows up clearly in the dσ/dMI spectrum with sizeable cross sections. The photon detection alone, summing all channels, is shown to reproduce quite accurately the strength and shape of the Λ(1405) resonance. When the reaction is performed in nuclei, the photon detection alone is still able to provide the resonance shape, opening ways for experimental investigation of medium modifications of the Λ(1405) properties.