$Z^{\prime }$ 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 $Z^{\prime }$ sector of a $U(1{)}_{B-L}$ 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 $Z_{B-L}^{\prime }\to e^{+}{e}^{-}$ and $Z_{B-L}^{\prime }\to \hat{I}{¼}^{+}\hat{I}{¼}^{-}$ decay channels. The comparison of the (irreducible) backgrounds with the expected backgrounds for the D$\tilde{A}˜$ experiment at the Tevatron validates our simulation. We propose an alternative analysis that has the potential to improve the D$\tilde{A}˜$ sensitivity. Electrons provide a higher sensitivity to smaller couplings at small $Z_{B-L}^{\prime }$ boson masses than do muons. The resolutions achievable may allow the $Z_{B-L}^{\prime }$ 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 $\int \mathcal{L}\sim 1$ 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 $M_{Z^{\prime }}$.

33 Pages, 14 figures and 8 tables. Updated Tevatron bounds and comparison to CDF and D0; improved methodology explanation; commented on inclusion of detector effects. Results changed only for the comparison to Tevatron. Corrected typos and updated bibliography to match published version in EPJC