Heavy-to-light meson transition form factors

Abstract

Hadronic heavy meson D and B decays into three mesons provide an interesting ground to study CP violation and strong interaction dynamical models. One important input, when calculating decay amplitudes within the quasi two-body factorization approach, are transition form factors between the heavy meson and contributing resonances. Following the dispersion relation framework used in our previous collaborations to determine the transition form factors for D to f(980)and B to f(980), we plan to extend these form factors to other cases in heavy meson decays. However, with the nonperturbative tools nowadays at our disposition, in particular the combined framework of Dyson-Schwinger and Bethe-Salpeter equations as well as the covariant light-front quark model, we expect more robust predictions with less model dependence and better covariance and Poincaré invariance properties. The theoretical framework is still the impulse approximation described by a triangle diagram sandwiched between two hadronic bound-state wave functions.We suggest to first study transition form factors between the D_0 and existing resonances in the D^0 to K^0_S K^+ K^- process, such as the D^0 to a_0(980) form factor, which will us help to analyze the constituent content of the scalar/isovector a_0(980) meson. Such a determination will help to reduce the current number of free parameters in Dalitz plot studies of the D^0 to K^0_S K^+ K^- decay. At a later stage, we shall also attempt to model meson-to-meson transition form factors entering annihilation amplitudes of this process at large momenta equal to the D^0 mass. (AU)