Enhanced B_s–B̅_s lifetime difference and anomalous like-sign dimuon charge asymmetry from new physics in B_s→τ⁺τ⁻

Abstract

New physics models that increase the decay rate of B_s→τ⁺τ⁻ contribute to the absorptive part of B_s–B̅_s mixing, and may enhance Δ Γ_s all the way up to its current experimental bound. In particular, the model with a scalar leptoquark can lead to a significant violation of the expectation Δ Γ_s≤Δ Γ_s (SM). It can even allow regions in the Δ Γ_s–β_s– parameter space that are close to the best fit obtained by CDF and D0 through B_s→J/ψφ. In addition, it can help explain the anomalous like-sign dimuon charge asymmetry observed recently by D0. A measurement of BR(B_s→τ⁺τ⁻) is thus crucial for a better understanding of new physics involved in B_s–B̅_s mixing.