The semileptonic exclusive B- and D-decays on the light-front

Abstract

Abstract We present a comprehensive account of a relativistic quark model on the light front which gives the form factors of weak hadronic currents among heavy pseudoscalar and vector mesons in the complete kinematic region 0 ≤ q 2 ≤ q max 2 . For the numerical investigations of the B → D ∗ lν l , B → ϱlν l , D → K ∗ lν l and D → ϱlν l semileptonic decays equal time wave functions using the updated values of the ISGW model are adopted. From the available experimental information on branching fractions BR(B → D ∗ lν l ) and BR ( B → ϱlν l ) the CKM parameters | V cb | and | V ub | are estimated to be | V cb | = 0.036 ± 0.002, | V ub | = 0.0033 ± 0.0005. It is shown that the q 2 distribution for the decay B → D ∗ lν l will allow for an accurate test of the value of | V cb |. The model is compared to the experimental data, QCD sum rules and lattice calculations.