$B_d-\bar{B}_d$ mixing vs. $B_s-\bar{B}_s$ mixing with the anomalous $Wtb$ couplings

Abstract

We explore the effects of the anomalous tbW couplings on the B d − Bd mixing and recently measured Bs − Bs mixing. The combined analysis of mixings via box diagrams with penguin decays provides strong constraints on the anomalous top quark couplings. We find the bound from the B d − Bd mixing data is stronger than that from the Bs − Bs mixing.

Interplay of t --> b W Decay and B_q Meson Mixing in Minimal Flavor Violating Models

“…In the present paper we consider anomalous tW d j interactions as a possible solution of these anomalies via their contribution to B d,s − Bd,s mixing amplitudes. Similar analyses have been attempted recently [9,10] using a subset of all possible effective tW d j operators. In particular, the authors of [9] have constrained contributions of two possible tW b operators using mostly B d oscillation parameter measurements, while in Ref.…”

“…Similar analyses have been attempted recently [9,10] using a subset of all possible effective tW d j operators. In particular, the authors of [9] have constrained contributions of two possible tW b operators using mostly B d oscillation parameter measurements, while in Ref. [10] they considered two tW s operators and concluded that the large non standard CP violating phase in B s − Bs mixing can be accommodated without violating B → X s γ constraints provided that the two NP operator contributions conspire in a way to mostly cancel in the later process while at the same time significantly affect the former.…”

“…In order to evaluate the hadronic matrix elements of the operators, we evolve the Wilson coefficients (9) from the matching scale at the top quark MS mass m t ≡ m t (m t ) to the low energy scale at bottom quark MS mass m b ≡ m b (m b ). Using results given in Ref.…”

“…After neglecting the masses of u and c quarks and enforcing unitarity of the CKM matrix we obtain the LO Wilson coefficients of effective Lagrangian in ( 8) (9) where…”

Unparticle contributions toBs−B¯smixing

“…Recently, the D0 collaboration announced the evidence for the charge asymmetry of the like-sign dimuon events [12]. For more discussions about B s -Bs mixing, see [13,14] and references therein.…”