Relaxing LHC constraints on the WR mass

Abstract

We study mass bounds of the WR gauge boson in generic left-right symmetric models. Assuming that the gauge bosons couple universally to quarks and leptons, we allow different gauge couplings gR = gL and mass mixing, V L CKM = V R CKM in the left and right sectors. Imposing constraints from collider experiments and K 0 , B d , Bs physics, we investigate scenarios where WR is lighter, or heavier than the right handed neutrino νR. In these scenarios, WR mass bounds can be considerably relaxed, while ZR mass bounds are much more stringent. In the case where MW R ≤ Mν R , the experimental constraints come from WR → tb and WR → jj channels, while if MW R ≥ Mν R , the dominant constraints come from WR → jj. The observed (expected) limits in the two-dimensional (MW R , Mν R ) mass plane excluded at 95% confidence level extend to approximately MW R = 3.1 (3.3) TeV in the ee channel and 3.3 (3.4) TeV in the (µµ) channel, for a large range of right-handed neutrino masses up to Mν R = 2.1 (2.1) TeV in the ee channel and 2.6 (2.5) in the (µµ) channel, representing a significant relaxation of the mass bounds. a

Cross-fertilising extra gauge boson searches at the LHC

“…To perform our numerical analysis, we have implemented the models presented in section 2 into FeynRules (version 2.3.35) [51] and converted them into leading-order UFO libraries [52,53]. Our new implementations are based on already publicly available ones [18,29,34,54,55], that we have harmonised with each other in the context of simplified versions of the various models (that are sufficient for our purpose). Hard-scattering partonlevel events have then been generated with MG5aMC (version 3.0.3) [56], and have been analysed with MadAnalysis 5 [57][58][59] (version 1.8.58).…”

Search for like-sign dileptons plus two jets signal in the framework of the manifest left-right symmetric model

“…There are already a number of simple changes to the manifest LRSM which relax these constraints and allow coexistence of LHC detectable WR alongside lower limits on at least part of the Higgs sector (e.g. by adding extra SU(2)R quark doublet or Higgs multiplets to the model, by using a higher dimensional operator, or by differentiating the left and right couplings and mixing matrices -see [49][50][51][52][53]). These adjustments may add new processes which lead to the LSD+2 signal.…”

Gravitational Wave Imprints of Left-Right Symmetric Model with Minimal Higgs Sector

“…The bound quoted above, however, can be significantly relaxed with some judicious choice of the relevant Yukawa couplings; see for example Refs. [23,126]. Typically, both light and heavy fermions couple to W R , which is a consequence of the seesaw formula.…”