Precise predictions for B→Xsℓ+ℓ− in the large q2 region

The inclusive B→Xsℓ+ℓ− decay rate in the large q2 region (q2>mψ′2) receives significant nonperturbative corrections. The resulting uncertainties can be drastically reduced by normalizing the rate to the B→Xuℓν¯ rate with the same q2 cut, which allows for much improved tests of short distance physics. We calculate this ratio, including the order 1/mb3 nonperturbative corrections and the analytically known NNLO perturbative corrections. Since in the large q2 region an inclusive measurement may be feasible via a sum over exclusive states, our results could be useful for measurements at LHCb and possibly for studies of B→Xdℓ+ℓ−.