Reconciling anomalous measurements inBs−B¯smixing: The role ofCPT-conserving and

Amol Dighe

¹

,

Diptimoy Ghosh

²

,

Anirban Kundu

³

et al.

Abstract

Recently observed anomalies in the Bs → J/ψφ decay and the like-sign dimuon asymmetry A b sl hint at possible new physics (NP) in the Bs − Bs mixing. We parameterize the NP with four modelindependent quantities: the magnitudes and phases of the dispersive part M12 and the absorptive part Γ12 of the NP contribution to the effective Hamiltonian. We constrain these parameters using the four observables ∆Ms, ∆Γs, the mixing phase β J/ψφ s , and A b sl . Our quantitative fit indicates that the NP should contribute a significant dispersive as well as absorptive part. In fact, models that do not contribute a new absorptive part are disfavored at more than 99% confidence level. We extend this formalism to include CPT violation, and show that CPT violation by itself, or even in presence of CPT-conserving new physics without an absorptive part, helps only marginally in the simultaneous resolution of these anomalies. The NP absorptive contribution to Bs − Bs mixing therefore seems to be essential, and would imply a large branching fraction for channels like Bs → τ + τ − .

Exploring new physics in the C 7-C 7′ plane

“…In 5 An interesting analysis was also presented in ref. [18], considering another subset of our observables but adding NP to one Wilson coefficient at a time.…”

“…The resulting picture has shown a very good overall agreement of all the constraints, apart from some discrepancies (direct CP asymmetries difference between B − → K − π 0 andB 0 → K − π + , B → τ ν versus sin 2β, B s meson mixing from J/Ψφ channel, and the dimuon asymmetry), which are still under experimental scrutiny but may be understood in terms of New Physics contributions [1][2][3][4][5].…”

“…[7], using a subset of our observables. 5 We will focus not only on the restrictive "flipped-sign" solution, but allow also for deviations in the modulus of C 7 . As it is well known, the sign of C 7 has an important impact on observables like the forward-backward asymmetry (A FB ) in the rare exclusive semileptonic decay B → K * µ + µ − , that is at present slightly at odds with the SM prediction.…”

Bdecay anomalies in an effective theory

“…[7] and further investigated in Refs. [8][9][10][11][12][13]. One might feel tempted to add to this list a hint of another anomaly: The branching ratio of H !…”

“…While such an effective operator-based study was undertaken in Refs. [10,13], the constraints on ÁM s were not correlated with those coming from the decay width difference ÁÀ s ; they were assumed to be independent numbers. The authors of Ref.…”