Light-cone distribution functions forBdecays at subleading order in1/mb

We construct the higher twist structure functions that describe inclusive b hadron decays in regions of phase space where the hadronic decay products carry high energy but have low invariant mass. We show that, for B meson decays, there are four new nonvanishing matrix elements of nonlocal operators. We show that to subleading twist these decays are parametrized in terms of four functions. We compute the tree-level matching for a general heavy-to-light current and apply it to $\overline{B}\to X_s\gamma .$ Using a simple model for these functions we estimate the subleading twist contributions to this decay.