Custodial bulk Randall-Sundrum model and B->K* l+ l'-

TL;DR

This paper investigates the custodial Randall-Sundrum model's impact on B->K* l+ l- decays, revealing potential new physics effects and deviations from the Standard Model, especially in B->K*ee decay observables.

Contribution

It provides a detailed analysis of flavor-changing-neutral-current phenomena in the custodial Randall-Sundrum model, including phenomenological constraints and predictions for B decay observables.

Findings

Only B->K*ee decay shows sizable new physics effects.

Zero position of the forward-backward asymmetry deviates by about 5% from SM.

Deviations of 10-20% from SM for KK gauge boson masses of 2-4 TeV.

Abstract

The custodial Randall-Sundrum model based on SU(2)_L X SU(2)_R X U(1)_(B-L) generates new flavor-changing-neutral-current (FCNC) phenomena at tree level, mediated by Kaluza-Klein neutral gauge bosons. Based on two natural assumptions of universal 5D Yukawa couplings and no-cancellation in explaining the observed standard model fermion mixing matrices, we determine the bulk Dirac mass parameters. Phenomenological constraints from lepton-flavor-violations are also used to specify the model. From the comprehensive study of B->K* l+ l'-, we found that only the B->K*ee decay has sizable new physics effects. The zero value position of the forward-backward asymmetry in this model is also evaluated, with about 5% deviation from the SM result. Other effective observables are also suggested such as the ratio of two differential (or partially integrated) decay rates of B->K*ee and B->K*mu mu. For the first KK gauge boson mass of M_A^(1)=2-4 TeV, we can have about 10-20% deviation from the SM results.