2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/81719We discuss an anomalous Lagrangian of the pi-rho-omega-a_1 system in the presence of external electroweak fields which is suitable for constructing the amplitude for the radiative muon capture by proton.7 pages, in Proceedings of the conference Mesons and Light Nuclei '98, Prague-Pruhonice, Czechia, 31 August-4 September 1998, eds. J. Adam et al., World Scientific, Singapore, 1999, p.490; 1 reference updated, errors removed from Eqs.50-53Nuclear Theorytext