Minimal flavor violations and tree level flavor changing neutral currents

Abstract

Consequences of a specific class of two Higgs doublet models in which the Higgs induced tree level flavour changing neutral currents (FCNC) display minimal flavour violation (MFV) are considered. These FCNC are fixed in terms of the CKM matrix elements and the down quark masses. The minimal model in this category with only two Higgs doublets has no extra CP violating phases but such a phase can be induced by adding a complex singlet. Many of the theoretical predictions are similar to other MFV scenario. The FCNC contribute significantly to B meson mixing and CP violation. Detailed numerical analysis to determine the allowed Higgs contributions to neutral meson mixings and the CKM parametersρ,η in their presence is presented. The Higgs induced phase in the B 0 d,s −B 0 d,s transition amplitude M d,s 12 is predicted to be equal for the B d and the B s systems. There is a strong correlation between phases in M d,s 12 and |V ub |. A measurable CP violating phase φ s = −0.18 ± 0.08 is predicted on the basis of the observed phase φ d in the B d system if |V ub | is large and close to its value determined from the inclusive b decays.

Higgs-mediated FCNCs: natural flavour conservation vs. minimal flavour violation

“…It is then straightforward to check that Z d ∝ M d and Z u ∝ M u for all cases in Eqs. (5), (6), and (8). This implies that quark mass terms and couplings to the neutral Higgs fields can be diagonalized simultaneously, resulting in the absence of tree-level FCNCs.…”

“…The question then arises how NFC (and GIM) are related to MFV, and vice versa. Motivated by a series of recent studies about the strengths of FCNCs in multi-Higgs doublet models [8][9][10][11][12], in this paper we present a detailed analysis of the relation between the NFC and MFV hypotheses. As we will show, while the two hypotheses are somehow equivalent at the tree-level, important differences arise when quantum corrections are included.…”

“…In this more general framework, the MFV hypothesis in its general formulation [5] turns out to be more stable in suppressing FCNCs than the hypothesis of NFC alone. This analysis will also give us the opportunity to compare the various formulations of MFV present in the literature and to clarify which of the multi-Higgs models proposed in [8][9][10] are consistent with the MFV principle, and thus are naturally protected against too large FCNCs.The phenomenological tests of these different concepts which can be obtained on the basis of meson-antimeson mixing observables, such as the CP-violating (CPV) observable ε K , the mass differences ∆M d,s , and the CP asymmetries S ψK S and S ψφ are also analysed. Beside being perfectly consistent with present data even for light Higgs boson masses, two-Higgs doublet models respecting the MFV hypothesis could even accommodate a large CP-violating phase in B s mixing, as hinted by CDF [13] and D0 [14,15].…”

“…In this more general framework, the MFV hypothesis in its general formulation [5] turns out to be more stable in suppressing FCNCs than the hypothesis of NFC alone. This analysis will also give us the opportunity to compare the various formulations of MFV present in the literature and to clarify which of the multi-Higgs models proposed in [8][9][10] are consistent with the MFV principle, and thus are naturally protected against too large FCNCs.…”

Search for New Physics in Bs-mixing

“…Refs. [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42]. TeVatron is continuing to take data and we will get more precise data from the upcomming experiments at LHC 43 or possibly at a SuperB-factory 44 running also at the Υ(5s)-resonance.…”