Nonperturbative corrections to B → Xsl+l- phase space restrictions

We study nonperturbative corrections up to O(1/m(b)(3)) in the inclusive rare B decay B --> X(s)l(+)l(-) by performing an operator product expansion. The values of the matrix elements entering at this order are unknown and introduce uncertainties into physical quantities. Imposing a phase space cut to eliminate the c (c) over bar resonances we find that the O(1/m(b)(3)) corrections introduce an O(10%) uncertainty in the measured rate. We also find that the contributions arising at O(1/m(b)(3)) are comparable to the ones arising at O(1/m(b)(2)) over the entire region of phase space. (C) 1999 Published by Elsevier Science B.V. All rights reserved.