It is shown that the inclusive rate of the rare weak radiative decays B B → Xsγ contains a series of nonperturbative corrections, whose 'short distance' scale is set by m-1c, rather than by m-1b. 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 〈B̄|b̄σ · Gb|B〉/m2c. Though the magnitude of this first correction is suppressed by a numerical coefficient, the sensitivity of the decay rate to the distance scale m-1c may significantly limit the accuracy of purely perturbative predictions for the rate.
|Original language||English (US)|
|Number of pages||4|
|Journal||Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics|
|State||Published - Apr 3 1997|
Bibliographical noteFunding Information:
I am thankful to Mikhail Shifman for useful discussions and to Mark Wise for pointing out a numerical error in an earlier version of this paper.T his work is supported, in part, by the DOE grant DE-AC02-83ER40105.