出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：In a relativistic potential model which has succeeded in reproducing the mass spectrum of the heavy-light mesons (charmed or bottom mesons), we have computed the radiative decay widths of the excited heavy-light mesons. The sum of the current quark mass and the constant term in the scalar potential were assumed to be 86MeV/c2 for the up and down quarks and 168MeV/c2 for the strange quark, which are much smaller than the emitted photon energy. In order to take into account the recoil effect of the mesons emitting a photon, we related the wave function of the heavy-light meson in the moving frame to the one in the rest frame. We have evaluated the matrix element of the electro-magnetic current in the Breit frame where the initial and final heavy-light mesons are moving with the velocity V and −V along the z-axis, respectively. We included the first order corrections in 1/mQ expansion to the wave function of the mesons. We have obtained the values 11keV and 0.56keV for the radiative decay widths of D∗0 and D∗+, respectively. In the non-relativistic arguments, the smallness of the radiative width of D∗+ compared to the one of D∗0 has been explained by the cancellation of the magnetic moments of the constituent quarks. The cancellation is much prominent for D∗+ s because of the heaviness of the strange quark mass in those arguments. On the other hand, our relativistic formula gives the value 0.72keV for the radiative decay width of D∗+ s , which is not smaller than that of D∗+. Large radiative decay widths were obtained for DsJ compared with non-relativistic works: G(D∗ s0(2317)+→D∗+ s +g )= 26keV, G(Ds1(2460)+ →D+s +g ) = 11keV, G(Ds1(2460)+ →D∗+ s +g ) = 100keV.
