Weak radiative decay ∧ < inf > b < /inf > → ∧ < inf > γ < /inf > in the heavy quark effective theory

Abstract

The weak radiative decay ∧b → ∧γ is studied in the heavy quark effective theory treating s-quark as heavy. This rare decay is induced by the short distance electromagnetic penguins. Including corrections of the order of (1/mQ), we obtain the transition matrix element and the corresponding decay width. The Isgur-Wise function is evaluated in the large Nc limit and the branching ratio obtained is 1.48 × 10-5.