Weak decay form factors of heavy pseudoscalar mesons within a light-front constituent quark model

Abstract

The transition form factors describing the semileptonic decays of heavy pseudoscalar mesons are investigated within a relativistic constituent quark model formulated on the light-front. For the first time the form factors are calculated in the whole accessible kinematical region, adopting meson wave functions derived from various effective q q interactions able to describe the meson mass spectra. It is shown that the decay rates of the B → Dℓ ν ℓ, D → Kℓ ν ℓ and D → πℓ ν ℓ weak decays are mainly governed by the effects of the confinement scale, whereas the B → πℓ ν ℓ decay rate is sensitive to the high-momentum components generated in the meson wave functions by the effective one-gluon-exchange interaction. Our results are consistent with available experimental data and predictions of lattice QCD calculations and QCD sum rules.