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

TL;DR

This paper investigates how Kaluza-Klein gauge bosons in warped extra-dimensional models influence meson mixing observables, highlighting potential signals detectable at the LHC and deviations from Standard Model predictions.

Contribution

It provides the first comprehensive analysis of KK gauge boson effects on Delta F=2 processes, including full operator basis and NLO RG running, with implications for LHC phenomenology.

Findings

KK gauge bosons with masses of 2-3 TeV can produce observable effects.

KK excitations of weak gauge bosons significantly impact B-meson mixing.

Predictions for new CP violation observables can differ markedly from SM expectations.

Abstract

After a brief theoretical introduction of the warped extra-dimensional model with custodial protection the results of arXiv:0809.1073 [hep-ph] are presented. In this work we analyze the impact of Kaluza-Klein (KK) gauge boson modes on Delta 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 epsilon_K, 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 Delta F=2 observables, such as S_\psi\phi and A_s^SL, which can differ significantly from their SM values.