Geng, Li Sheng; Oset Báguena, Eulogio Perfil; Döring, Michael  
This document is a artículoDate2007  
We evaluate theoretically the radiative decay widths into γΛ and γΣ0 of the two poles of the Λ(1405) found in chiral unitary theories and we find quite different results for each of the two poles. We show that, depending on which reaction is used to measure the Λ(1405) radiative decays, one gives more weight to one or the other pole, resulting in quite different shapes in the γΛ(Σ0) invariant mass distributions. Our results for the highenergy pole agree with those of the empirical determination of the γΛ and γΣ0 radiative widths (based on an isobar model fitting of the K−p atom data), which are sometimes referred to as ``experimental data''. We have made a detailed study of the K−p→π0γΛ(Σ0) and π−p→K0γΛ(Σ0) reactions and have shown that they, indeed, lead to different shapes for the γΛ(Σ0) invariant mass distributions.  
Geng, Li Sheng Oset Báguena, Eulogio Döring, Michael 2007 The radiative decay of the Lambda(1405) and its twopole structure European Physical Journal A 32 2 201 211 

http://dx.doi.org/10.1140/epja/i2007103710 