LHC constraints on W′, Z′ that couple mainly to third generation fermions

Abstract

We use the results of CMS and ATLAS searches for resonances that decay to tau nu or tb and tau(+)tau(-) or t (t) over bar final states to constrain the parameters of non-universal W' and Z' gauge bosons that couple preferentially to the third generation. For the former we consider production from c (b) over bar annihilation and find very weak constraints on the strength of the interaction and only for themass range between 800 and 1100 GeV from the pp -> tau(h)p(T)(miss) channel. The constraints on the latter are much stronger and arise from both t (t) over bar and tau(+)tau(-) production. Treated separately, we find that the weak constraints on the W' still permit an explanation of the R(D-(star)) anomalies with a light sterile neutrino whereas the stronger constraints on the Z' exclude significant light sterile neutrino contributions to the K -> pi nu(nu) over bar rates. Within specific models the masses of W' and Z' are of course related and we briefly discuss the consequences.