Constraints on new physics in $B-\bar{B}$ mixing in the light of recent LHCb data.

Abstract

We perform model-independent statistical analyses of three scenarios accommodating new physics (NP) in ΔF=2 flavor-changing neutral current amplitudes. In a scenario in which NP in Bd-B̅ d mixing and Bs-B̅ s mixing is uncorrelated, we find the parameter point representing the standard model disfavored by 2.4 standard deviations. However, recent LHCb data on Bs neutral meson mixing forbid a good accommodation of the DØ data on the semileptonic CP asymmetry ASL. We introduce a fourth scenario with NP in both M12d,s and Γ12d,s, which can accommodate all data. We discuss the viability of this possibility and emphasize the importance of separate measurements of the CP asymmetries in semileptonic Bd and Bs decays. All results have been obtained with the CKMfitter analysis package, featuring the frequentist statistical approach and using Rfit to handle theoretical uncertainties.