Particle-antiparticle mixing, CP violation and rare K and B decays in a minimal theory of fermion masses

作者：Buras Andrzej J^*; Girrbach Jennifer; Ziegler Robert

来源：The Journal of High Energy Physics, 2013, 2013(4): 168.

DOI：10.1007/JHEP04(2013)168

• Rare Decays
• Beyond Standard Model
• CP violation

We present a detailed study of Delta F = 2 observables and of rare K+(K-L) and B-s,B-d meson decays in a "Minimal Theory of Fermion Masses" (MTFM). In this theory Yukawa couplings are generated through the mixing with heavy vectorlike (VF) fermions. This implies corrections to the SM quark couplings to W-+/-, Z(0) and Higgs so that FCNC processes receive contributions from tree level Z(0) and Higgs exchanges and W-+/- bosons couple to right-handed quarks. In a particular version of this model in which the Yukawa matrix lambda(D) in the heavy down fermion sector is unitary, lambda(U) = 1 and M = M-VF is fixed, only three real and positive definite parameters describe New Physics (NP) contributions to all Delta F = 2 and Delta F = 1 observables in K and B-s,B-d systems once the known quark masses and the CKM matrix are correctly reproduced. For M >= 1TeV NP contributions to B-s,d(0) - (B) over bar (0)(s,d) mixings are found to be very small. While in principle NP contributions to epsilon(K) and Delta F = 1 processes could be large, the correlation between epsilon(K) and K-L -> mu(+)mu(-) eliminates basically NP contributions to epsilon(K) and right-handed current contributions to Delta F = 1 FCNC observables. We find CMFV structure in B-s,B-d decays with B(B-s,B-d -> mu(+)mu(-)) uniquely enhanced for M = 3 TeV by at least 35% and almost up to a factor of two over their SM values. Also B(K+ -> pi(+)nu(nu) over bar) and B(K-L -> pi(0)nu(nu) over bar) are uniquely enhanced by similar amount but the correlation between them differs from the CMFV one. We emphasize various correlations between K and B-s,B-d decays that could test this scenario. The model favours gamma approximate to 68 degrees, vertical bar V-ub vertical bar approximate to 0.0037, S-psi KS approximate to 0.72, S-psi phi approximate to 0.04 and 4.2 x 10(-9) = B(B-s -> mu(+)mu(-)) <= 5.0 x 10(-9) for M = 3-4 TeV.

• 出版日期2013-4