A Constituent Quark-Meson Model for Heavy Meson Decays

I describe a model for heavy meson decays based on an effective quark-meson lagrangian. I consider the heavy mesons S with spin and parity J P = (1 + ,0 + ), H with J P = (1 − ,0 − ) and Twith J P = (2 + ,1 + ), i.e. S and P wave heavy-light mesons. The model is constrained by the known symmetries of QCD in the mQ → ∞ for the heavy quarks and chiral symmetry in the light quark sector. Using a very limited number of free parameters it is possible to compute several phenomenological quantities, e.g. the leptonic B and B ∗∗ decay constants; the three universal Isgur-Wise form factors: ξ, τ3/2, τ1/2, describing the semi-leptonic decays B → D (∗) lν, B → D ∗∗ lν; the strong and radiative D ∗ decays; the weak semi-leptonic decays of B and D into light mesons: π, ρ, A1. An overall agreement with data, when available, is achieved.