Flavor physics beyond the standard model

We examine possible New Physics impact on certain heavy quark flavor involving processes, such as charm and bottom strange meson-antimeson oscillations and leptonic meson decays. Also, we consider a possibility of explaining within a two-Higgs doublet extension of the Standard Model the quark and charged lepton mass hierarchy. We show that the experimental value of the lifetime difference in D⊃0⊃-anti-D⊃0⊃ mixing may be due to destructive interference of the Standard Model and New Physics contributions. We examine next possible correlations between the New Physics contribution to B⊂s⊂ mixing mass difference and B⊂s⊂ ⊃+⊃-⊃ leptonic decay .We show that these correlations tend to rule out possible large New Physics contribution to B⊂s⊂ μ⊃+⊃-⊃ . We propose also to explain within a general two-Higgs doublet extension of the Standard Model the quark and lepton mass hierarchy by imposing some basis invariant conditions on the quark and lepton Yukawa matrices with no or little hierarchy in Yukawa couplings

Relating B_s Mixing and B_s -> mu+mu- with New Physics

We perform a study of the Standard Model (SM) fit to the mixing quantities $\Delta M_{B_s}$, and $\Delta \Gamma_{B_s}/\Delta M_{B_s}$ in order to bound contributions of New Physics to $B_s$ mixing. We then use this to explore the branching fraction of $B_{s} \to \mu^+\mu^-$ in certain models of New Physics (NP). In most cases, this constrains NP amplitudes for $B_{s} \to \mu^+\mu^-$ to lie below the SM component.Comment: 27 pages, 5 figures; corrected misprints, updated numerical inputs and new reference

The flavor puzzle in multi-Higgs models

We reconsider the flavor problem in the models with two Higgs doublets. By studying two generation toy models, we look for flavor basis independent constraints on Yukawa couplings that will give us the mass hierarchy while keeping all Yukawa couplings of the same order. We then generalize our findings to the full three generation Standard Model. We find that we need two constraints on the Yukawa couplings to generate the observed mass hierarchy, and a slight tuning of Yukawa couplings of order 10%, much less than the Standard Model. We briefly study how these constraints can be realized, and show how flavor changing currents are under control for $K-\bar{K}$ mixing in the near-decoupling limit.Comment: 26 pages, typos are corrected, references are added, the final versio

Relating B_S Mixing and B_S to mu+mu- with New Physics

We perform a study of the standard model fit to the mixing quantities {Delta}M{sub B{sub s}}, and {Delta}{Lambda}{sub B{sub s}}/{Delta}M{sub B{sub s}} in order to bound contributions of new physics (NP) to B{sub s} mixing. We then use this to explore the branching fraction of B{sub s} {yields} {mu}{sup +}{mu}{sup -} in certain models of NP. In most cases, this constrains NP amplitudes for B{sub s} {yields} {mu}{sup +}{mu}{sup -} to lie below the standard model component