Radiative decays in covariant confined quark model* *Supported by Ho Chi Minh City University of Technology and Education (T2022-26)

Abstract

Radiative decays are revisited in light of new experimental data from the BaBar and BESIII Collaborations. The radiative couplings encoding nonperturbative QCD effects are calculated in the framework of the covariant confined quark model developed by us. We compare our results with other theoretical studies and experimental data. The couplings (in ) and calculated in our model agree with the corresponding experimental data and . The most interesting case is the decay , for which a recent prediction based on light-cone sum rules at next-to-leading order deviates from the first (and only to date) lattice QCD result at nearly . Our calculation yields , which falls somehow between the two mentioned results, although it is larger than those predicted in other studies using quark models or QCD sum rules.