We present a theoretical reappraisal of the branching ratios and CP
asymmetries for the decays B→Xq​ℓ+ℓ−, with q=d,s, taking
into account current theoretical uncertainties in the description of the
inclusive decay amplitudes from the long-distance contributions, an improved
treatment of the renormalization scale dependence, and other parametric
dependencies. Concentrating on the partial branching ratios ΔB(B→Xq​ℓ+ℓ−), integrated over the invariant dilepton mass region 1GeV2≤s≤6GeV2, we calculate theoretical precision on the
charge-conjugate averaged partial branching ratios =(ΔB(B→Xq​ℓ+ℓ−)+ΔB(Bˉ→Xˉq​ℓ+ℓ−))/2, CP asymmetries in partial decay rates
(aCP​)q​=(ΔB(B→Xq​ℓ+ℓ−)−ΔB(Bˉ→Xˉq​ℓ+ℓ−))/(2), and the ratio of the
branching ratios ΔR=/.
For the central values of the CKM parameters, we find =(2.22−0.30+0.29​)×10−6, =(9.61−1.47+1.32​)×10−8, (aCP​)s​=−(0.19−0.19+0.17​), (aCP​)d​=(4.40−4.46+3.87​), and ΔR=(4.32±0.03). The dependence of and ΔR on the CKM parameters is worked out and the resulting constraints on
the unitarity triangle from an eventual measurement of ΔR are
illustrated.Comment: 18 pages, 7 figures (require epsf.sty