Probing RS scenarios of flavour at the LHC via leptonic channels

Abstract

We study a purely leptonic signature of the Randall-Sundrum scenario with Standard Model fields in the bulk at LHC: the contribution from the exchange of Kaluza- Klein (KK) excitations γ (n) , Z (n) of gauge bosons to the clear Drell-Yan reaction pp → γ/Z → l + l − . We show that, even with the low luminosities of the LHC initial regime, this contribution is detectable with the ATLAS apparatus for KK masses around the TeV scale and for sufficiently large lepton couplings to KK gauge bosons . Such large couplings can be compatible with electroweak precision data on the Z ¯ ff coupling in the framework of the custodial O(3) symmetry recently proposed, for specific configurations of lepton local- izations along the extra dimension. These configurations can simultaneously reproduce the correct lepton masses, while generating acceptably small flavour changing neutral current effects.