Second-order direct CP asymmetry in B(s)→Xℓν

A direct CP asymmetry in inclusive semileptonic B(s) decays vanishes by CPT to lowest order in weak interactions. Calculating the asymmetry at second-order-weak interactions in the Cabibbo-Kobayashi-Maskawa framework we find Asl=(−3.2±0.9)×10−9. A maximal asymmetry which is two orders of magnitude larger is estimated in a left-right-symmetric model. This quite generic upper bound implies negligible effects on wrong-sign lepton asymmetries in B0 and Bs decays.