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 the WR 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→ℓ±jj, are highly collimated, forming a single neutrino jet (jN). The final-state collider signature is then ℓ±jN, instead of the widely studied ℓ±ℓ±jj. 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=3(4)[5] TeV and mass ratio of (mN/MWR)<0.1 can be discovered with a 5-6σ statistical significance at 13 TeV after 10(100)[2000] 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=15(30) with approximately 100 fb-1 (10 ab-1). Conversely, with 0.9(10)[150] fb-1 of 13 TeV data, MWR<3(4)[5] TeV and (mN/MWR)<0.1 can be excluded at 95% C.L.; with 100 fb-1 (2.5 ab-1) of 100 TeV data, MWR<22(33) TeV can be excluded.