LHC di-lepton searches for Z′ bosons which explain measurements of b → sl+l− transitions

Abstract

Several current measurements of b→sl+l− processes are in tension with Standard Model predictions, whereas others (e.g. RK and RK⁎) are in reasonable agreement with them. We examine some recent Z′ models that fit the data as a whole appreciably better than does the Standard Model, confronting the models with ATLAS resonance searches in the e+e− and μ+μ− channels. The models are constrained by both channels; we find that the searches rule out less than one fifth of the allowed range of MZ′. We estimate that the HL-LHC can roughly double the current sensitivity in MZ′, but to cover the whole of the parameter space would take a more powerful machine, such as a 100 TeV pp collider.