O( m −2 c ) nonperturbative corrections to the inclusive rate of the decay B→ X s γ
Abstract
It is shown that the inclusive rate of the rare weak radiative decays
B→
X
s
γ
contains a series of nonperturbative corrections, whose `short distance' scale is set by
m
−1
c
, rather than by
m
−1
b
. The first correction in this series is expressed through the chromomagnetic interaction of the
b
quark inside the
B
meson and the relative magnitude of the effect is determined by the ratio
<
B
¯
¯
¯
¯
|
b
¯
σ⋅Gb|B>/
m
2
c
. Though the magnitude of this first correction is suppressed by a numerical coefficient, the sensitivity of the decay rate to the distance scale
m
−1
c
may significantly limit the accuracy of purely perturbative predictions for the rate.