K and B meson mixing in warped extra dimensions with custodial protection

Abstract

After a brief theoretical introduction of the warped extra-dimensional model with custodial protection the results of [1] are presented. In this work we analyze the impact of Kaluza-Klein (KK) gauge boson modes on ∆F = 2 observables, for the first time considering the full operator basis and including NLO renormalization group running. It is pointed out that the dominant contribution in the B-system does not come from the KK gluon, but that contributions from KK excitations of the weak gauge bosons are competitive. In a numerical analysis we assess the amount of fine-tuning necessary for obtaining realistic values for quark masses and mixings and at the same time realistic values for ǫK , the measure for CP violation in K meson mixing. We are able to show that a mass of the lightest KK gauge boson of 2-3 TeV, and hence in the reach of the LHC, is still possible for moderate fine-tuning. These results enable us to make predictions for not yet measured ∆F = 2 observables, such as S ψφ and A SL s , which can differ significantly from their SM values.

Manifestations of warped extra dimension in rare charm decays and asymmetries

“…K, B and D mesons. Signatures of this class of models along with the correlations generated by the same in K and B physics have been studied in great detail by [21][22][23][24][25][26][27][28][29][30]. They have extracted the flavour structure of these models as well as the fermion mass hierarchy which is consistent with current experimental bounds.…”

A comparative study of contributions to ϵ K in the RS model

“…As an outcome of our analysis we have shown that while Higgs FCNCs have an impact on ǫ K as was already pointed out in [6], their contribution for a brane Higgs is dwarfed by the contribution of KK gluons even in the most favorable scenario for the Higgs contributions. For a brane Higgs scenario with reasonable choices fundamental Yukawa couplings the bound on the KK scale implied by the presence of tree-level Higgs exchanges is found to be 5 − 7 TeV, to be compared to the corresponding bounds for KK gluon exchange that are given by M KK (9 TeV − 14 TeV) for g * = 3 and M KK (19 TeV − 32 TeV) for g * = 6 (see also [4,7,20]).…”

“…20) and their numerical values at the lattice scale µ L = 2.0 GeV are given by[13] B 2 = 0.679 , B 3 = 1.055 , B 4 = 0.810 , B 5 = 0.562 . (3.21)…”

Patterns of Flavour Violation in the RSc Model, the LHT Model and Supersymmetric Flavour Models

“…On the other hand SM-like value of S ψφ will open the road for large enhancements of these branching ratios that could be tested by KOTO at J-Parc and NA62 at CERN, respectively. Reviews of our work on the RSc model appeared in [40,41,36,42,43,44].…”