Z′ discovery potential at the LHC in the minimal B–L extension of the standard model

Abstract

We present the Large Hadron Collider (LHC) discovery potential in the Z′ sector of a $U(1)_{B\mbox{--}L}$ enlarged Standard Model (that also includes three heavy Majorana neutrinos and an additional Higgs boson) for $\sqrt{s}=7$, 10 and 14 TeV centre-of-mass (CM) energies, considering both the $Z'_{B\mbox{--}L}\rightarrow e^{+}e^{-}$ and $Z'_{B\mbox{--}L}\rightarrow\mu^{+}\mu^{-}$ decay channels. The comparison of the (irreducible) backgrounds with the expected backgrounds for the DØ experiment at the Tevatron validates our simulation. We propose an alternative analysis that has the potential to improve the DØ sensitivity. Electrons provide a higher sensitivity to smaller couplings at small $Z'_{B\mbox{--}L}$ boson masses than do muons. The resolutions achievable may allow the $Z'_{B\mbox{--}L}$ boson width to be measured at smaller masses in the case of electrons in the final state. The run of the LHC at $\sqrt{s}=7$ TeV, assuming at most $\int\mathcal{L} \sim1$ fb⁻¹, will be able to give similar results to those that will be available soon at the Tevatron in the lower mass region, and to extend them for a heavier M _Z′.