Recently, Neubert has suggested that a certain class of nonperturbative corrections dominates the shape of the electron spectrum in the end point region of semileptonic $B$ decay. Perturbative QCD corrections are important in the end point region. We study the effects of these corrections on Neubert's proposal. A connection between the end point of the electron spectrum in semileptonic $B$ decay and the photon spectrum in $b\to s\gamma$ is outlined.

• Received 20 December 1993

DOI:https://doi.org/10.1103/PhysRevD.49.4553