Subleading light-cone distribution functions in the decays Lambda(b) - X-S gamma and Lambda(b) - X-u l(nu)over-bar(l)

摘要

In this Letter we investigate the subleading twist corrections to the photon energy spectrum in the decay Lambda(b) --> X(S)gamma and to the lepton energy spectrum in Lambda(b) --> X(u)l (nu;) over bar (l). As a first step we rederive the matching coefficients of the subleading twist using a much simpler method. Parametrizing the matrix elements for Lambda(b) and using reparametrization invariance, we show that the energy spectra close to the endpoints are given in terms of only a single universal function. (C) 2003 Elsevier Science B.V. All rights reserved. References: 16