Decay constants and radiative decays of heavy mesons in light-front quark model

Abstract

We investigate the magnetic dipole decays $V\to P\gamma$ of various heavy-flavored mesons such as $(D,D^{*},D_s,D_s^{*},{\eta }_c,J/\psi )$ and $(B,B^{*},B_s,B_s^{*},{\eta }_b,{\rm Y})$ using the light-front quark model constrained by the variational principle for the QCD-motivated effective Hamiltonian. The momentum dependent form factors $F_{VP}(q^2)$ for $V\to P{\gamma }^{*}$ decays are obtained in the $q^{+}=0$ frame and then analytically continued to the timelike region by changing ${\mathbf{q}}_{\perp }$ to $i{\mathbf{q}}_{\perp }$ in the form factors. The coupling constant $g_{VP\gamma }$ for real photon case is then obtained in the limit as $q^2\to 0$, i.e. $g_{VP\gamma }=F_{VP}(q^2=0)$. The weak decay constants of heavy pseudoscalar and vector mesons are also calculated. Our numerical results for the decay constants and radiative decay widths for the heavy-flavored mesons are overall in good agreement with the available experimental data as well as other theoretical model calculations.