Semi-inclusive decays Λb→Xc+(Ds,Ds*) at O(as) including Λb and Ds* polarization effects -: art. no. 094026

In the leading order of the (1/m(b))-expansion in HQET the dominant contribution to the semi-inclusive decays of polarized Lambda(b) baryons into the charm-strangeness mesons D-s and D-s(*) is given by the partonic process b(up arrow)-->c+(D-s(-),D-s(*-)). Using standard values for the parameters of the process one expects a rather large branching ratio of approximate to8% into these two channels. In the factorization approximation the semi-inclusive decay of a polarized Lambda(b) is governed by three unpolarized and four polarized structure functions for which we determine the nonperturbative O(1/m(b)(2)) corrections and the O(alpha(s)) radiative corrections. We find that the perturbative and nonperturbative corrections amount to approximate to10% and approximate to3%, respectively. The seven structure functions can be measured through an analysis of the joint decay distributions of the process involving the polarization of the Lambda(b) and the decays D-s(*-)-->D-s(-)+gamma and D-s(*-)-->D-s(-)+pi(0) for which we provide explicit forms. We also provide numerical results for the Cabibbo-suppressed semi-inclusive decays Lambda(b)-->X-u+(D-s,D-s(*)).