Inclusive B¯→Xsℓ+ℓ− at the LHC: theory predictions and new-physics reach

We present theoretical predictions for observables in inclusive B¯→X_sℓ⁺ℓ⁻ suitable for measurements at hadron colliders through a sum-over-exclusive approach. At low q² we calculate the branching ratio and three angular observables. At high q² we provide the branching ratio and the ratio of the B¯→X_sℓ⁺ℓ⁻ rate with respect to the inclusive B¯→X_uℓν¯ rate with the same phase-space cut. We compare our predictions to the B factory measurements and also to an extraction of the experimental rate through a sum-over-exclusive method using branching ratios of the exclusive B¯→K^∗μ⁺μ⁻ modes measured at LHCb. We find a consistent picture comparing Standard Model theory and experiment. As such, our analysis does not support a recent claim about a deficit in the inclusive branching ratio in the high-q² region. Finally, we present current model-independent bounds on new physics and emphasize the potential of complementary analyses of B¯→X_sℓ⁺ℓ⁻ at Belle II and the LHC.