$\bar B\to X_s \gamma$ with a warped bulk Higgs

TL;DR

This paper investigates the impact of Randall-Sundrum models with a bulk Higgs on the decay process $ar B o X_s\gamma$, analyzing tree-level, one-loop, and QCD effects to determine their influence on branching fractions.

Contribution

It provides a detailed calculation of RS model corrections to $ar B o X_s\gamma$, including both minimal and custodial models, considering various loop and QCD effects.

Findings

RS corrections can be significant with large Yukawas and moderate KK scales

Small Yukawas lead to negligible RS contributions within current experimental limits

The study quantifies the parameter space where RS effects are observable

Abstract

We study the decay $\bar B\to X_s\gamma$ in Randall-Sundrum models with an IR-localised bulk Higgs. The two models under consideration are a minimal model as well as a model with a custodial protection mechanism. We include the effects of tree- and one-loop diagrams involving 5D gluon and Higgs exchanges as well as QCD corrections arising from the evolution from the Kaluza-Klein scale to the typical scale of the decay. We find the RS corrections to the branching fraction can be sizeable for large Yukawas and moderate KK scales $T$; for small Yukawas the RS contribution is small enough to be invisible in current experimental data.