Corrections of order ΛQCD2mc2 to inclusive rare B decays Original Research Article

We calculate non-perturbative O(ΛQCD2mc2) corrections to the dilepton invariant mass spectrum and the forward-backward charge asymmetry in B → Xse+e− decay using a heavy quark expansion approach. The method has recently been used to estimate long-distance effects in B → Xsγ. We generalize this analysis to the case of non-vanishing photon invariant mass, q2 ≠ 0, relevant for the rare decay mode B → Xse+e−. In the phenomenologically interesting q2 region away from the cc resonances, the heavy quark expansion approach should provide a reasonable description of possible non-perturbative corrections. In particular this picture is preferable to the model-dependent approach relying on the tails of Breit-Wigner resonances, which has been employed so far in the literature to account for these effects. We find that the O(ΛQCD2mc2) corrections to the dilepton invariant mass spectrum and to the forward-backward asymmetry in B → Xse+e− amount to several percent at most for q2mb2 ≲ 0.3 and q2mb2 ≳ 0.6. The O(ΛQCD2mc2) correc tion to the B → Xsγ decay rate is also computed and found to be +3%, which agrees in magnitude with previous calculations. Finally, we comment on long-distance effects in B → Xsνν−, which in this case are extremely suppressed due to the absence of virtual photon contributions.