Covariant Light-Front Approach for s-wave and p-wave Mesons: Its Application to Decay Constants and Form Factors

摘要

We study the decay constants and form factors of the ground-state s-wave andlow-lying p-wave mesons within a covariant light-front approach. Numericalresults of the form factors for transitions between a heavy pseudoscalar mesonand an s-wave or p-wave meson and their momentum dependence are presented indetail. In particular, form factors for heavy-to-light and B to D**transitions, where D** denotes generically a p-wave charmed meson, are comparedwith other model calculations. The experimental measurements of the decays B^-to D** pi^- and B to D D**_s are employed to test the decay constants of D**_sand the B to D** transition form factors. The heavy quark limit behavior of thedecay constants and form factors is examined and it is found that therequirement of heavy quark symmetry is satisfied. The universal Isgur-Wise (IW)functions, one for s-wave to s-wave and two for s-wave to p-wave transitions,are obtained. The values of IW functions at zero recoil and their slopeparameters can be used to test the Bjorken and Uraltsev sum rules.