Radiative decays of mesons in the quark model: relativistic and non-relativistic approaches

Different conclusions about quark nature of f0(980) based on the analysis of data on the reaction �(1020) → f0(980) make it necessary to perform detailed comparison of formulae used by various groups for the calculation of partial widths of radiative decays. We carry out a comparative analysis of methods of calculation of radiative decays like � → f0 and � → � performed by F.E. Close et al., Phys. Rev. D 65, 092003 (2002), and A.V. Anisovich et al., Eur. Phys. J. A 12, 103 (2001); Yad. Fiz. 65, 523 (2002).