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Subleading Light-cone distributions functions in the decays Lambda(b) --> X(s) Gamma and Lambda(b) --> X(u) Lepton Anti-Nu

In this paper we investigate the subleading twist corrections to the photon energy spectrum in the decay Lambda_b -> X_s γand to the lepton energy spectrum in Lambda_b -> X_u l \barν. 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.