K_0^*(1430) twist-2 distribution amplitude and B_s,D_s rightarrow K_0^*(1430) transition form factors

Abstract

Based on the scenario that the K_0^*(1430) is viewed as the ground state of sbar{q} or qbar{s}, we study the K_0^*(1430) leading-twist distribution amplitude (DA) phi _{2;K_0^*}(x,mu ) with the QCD sum rules in the framework of background field theory. A more reasonable sum rule formula for xi -moments langle xi ^nrangle _{2;K_0^*} is suggested, which eliminates the influence brought by the fact that the sum rule of langle xi ^0_prangle _{3;K_0^*} cannot be normalized in whole Borel region. More accurate values of the first ten xi -moments, langle xi ^nrangle _{2;K_0^*} (n = 1,2,ldots ,10), are evaluated. A new light-cone harmonic oscillator (LCHO) model for K_0^*(1430) leading-twist DA is established for the first times. By fitting the resulted values of langle xi ^nrangle _{2;K_0^*} (n = 1,2,ldots ,10) via the least squares method, the behavior of K_0^*(1430) leading-twist DA described with LCHO model is determined. Further, by adopting the light-cone QCD sum rules, we calculate the B_s,D_s rightarrow K_0^*(1430) transition form factors and branching fractions of the semileptonic decays B_s,D_s rightarrow K_0^*(1430) ell nu _ell . The corresponding numerical results can be used to extract the Cabibbo-Kobayashi-Maskawa matrix elements by combining the relative experimental data in the future.