Constraints on the malaphoric $B_3-L_2$ model from di-lepton resonance searches at the LHC

We confront the malaphoric $$B_3-L_2$$ B 3 - L 2 model with bounds coming from a search for resonances in the di-lepton channels at the 13 TeV LHC. In contrast to the original $$B_3-L_2$$ B 3 - L 2 model, the $$Z^\prime $$ Z ′ of the malaphoric $$B_3-L_2$$ B 3 - L 2 model has sizeable couplings to the lighter two families; these originate from order unity kinetic mixing with the hypercharge gauge boson and ameliorate the fit to lepton flavour universality measurements in B-meson decays. The $$Z^\prime $$ Z ′ coupling to the first two families of quark means that the resulting constraints from resonant di-lepton searches are stronger. Nevertheless, we find that for $$M_{Z^\prime }>2.8$$ M Z ′ > 2.8 TeV there remains a non-negligible region of allowed parameter space where the model significantly improves upon several Standard Model predictions for observables involving the $$b \rightarrow s l^+ l^-$$ b → s l + l - transition. We estimate that the 3000 fb $$^{-1}$$ - 1 HL-LHC will extend this sensitivity to $$M_{Z^\prime }= 4.2$$ M Z ′ = 4.2 TeV.