Radiative decays of the Λ(1520) as a dynamically generated resonance

Inspired by the latest BESIII measurement of the $\Lambda(1520)\to\gamma\Sigma^0$ radiative decay, we systematically study the decays $\Lambda(1520)\to\gamma\Lambda(\Sigma^0)$ within the chiral unitary approach, where the $\Lambda(1520)$ is treated as a dynamically generated resonance from meson-baryon interactions. Compared with previous chiral unitary studies, we adopt dimensional regularization for $S$-wave loop integrals to preserve gauge invariance and, for the first time, include Feynman diagrams with photon coupling to intermediate baryons. Our calculated partial decay width $\Gamma(\Lambda(1520)\to\gamma\Sigma^0)$ agrees well with the new BESIII data, whereas the predicted $\Gamma(\Lambda(1520)\to\gamma\Lambda)$ is considerably smaller than the CLAS experimental result. By comparing our results with predictions from various quark models, we discuss the internal nature of the $\Lambda(1520)$ resonance, highlight its complex component structure, and stress the need for more refined theoretical frameworks and further experimental measurements.