Constituent quark-meson model for heavy-meson processes

We describe the effective heavy meson Lagrangian for $S$- and $P$-wave heavy-light mesons in terms of a model based on meson-quark interactions, where mesonic transition amplitudes are represented by diagrams with heavy mesons attached to loops containing heavy and light constituent quarks. The model is relativistic and incorporates the heavy quark symmetries. The universal form factors of the heavy meson transition amplitudes are calculated together with their slopes and compared to existing data and limits. As further applications of the model, strong and radiative decays of $D^{*}$ and $B^{*}$ are considered. The agreement with data is surprisingly good and shows that the model offers a viable alternative to effective meson Lagrangians which require a larger number of input parameters.