Neutrino jets from high-mass WR gauge bosons in TeV-scale left-right symmetric models

Abstract

We reexamine the discovery potential at hadron colliders of high-mass right-handed (RH) gauge bosons WR—an inherent ingredient of left-right symmetric models (LRSM).We focus on the regime where theWR is very heavy compared to the heavy Majorana neutrino N, and we investigate an alternative signature for WR → N decays. The produced neutrinos are highly boosted in this mass regime. Subsequently, their decays via off-shell WR bosons to jets, i.e., N → ljj, are highly collimated, forming a single neutrino jet ðjNÞ. The final-state collider signature is then ljN, instead of the widely studied lljj. Present search strategies are not sensitive to this hierarchical mass regime due to the breakdown of the collider signature definition. We take into account QCD corrections beyond next-to-leading order (NLO) that are important for high-mass Drell-Yan processes at the 13 TeV Large Hadron Collider (LHC). For the first time, we evaluate WR production at NLO with threshold resummation at next-to-next-to-leading logarithm (NNLL) matched to the threshold-improved parton distributions. With these improvements, we find that a WR of mass MWR ¼ 3ð4Þ½5 TeV and mass ratio of ðmN=MWR Þ < 0.1 can be discovered with a 5–6σ statistical significance at 13 TeVafter 10ð100Þ½2000 fb−1 of data. Extending the analysis to the hypothetical 100 TeV Very Large Hadron Collider (VLHC), 5σ can be obtained for WR masses up to MWR ¼ 15ð30Þ with approximately 100 fb−1 (10 ab−1). Conversely, with 0.9ð10Þ½150 fb−1 of 13 TeV data, MWR <3ð4Þ½5 TeV and ðmN=MWR Þ < 0.1 can be excluded at 95% C.L.; with 100 fb−1 (2.5 ab−1) of 100 TeV data, MWR < 22ð33Þ TeV can be excluded.