Signal of right-handed charged gauge bosons at the LHC?

Abstract

We point out that the recent excess observed in searches for a right-handed gauge boson ${W}_{R}$ at CMS can be explained in a left-right symmetric model with $D$-parity violation. In a class of SO(10) models, in which $D$ parity is broken at a high scale, the left-right gauge symmetry breaking scale is naturally small, and at a few TeV the gauge coupling constants satisfy ${g}_{R}\ensuremath{\approx}0.6{g}_{L}$. Such models therefore predict a right-handed charged gauge boson ${W}_{R}$ in the TeV range with a suppressed gauge coupling as compared to the usually assumed manifest left-right symmetry case ${g}_{R}={g}_{L}$. The recent CMS data show excess events which are consistent with the cross section predicted in the $D$-parity breaking model for $1.9\text{ }\text{ }\mathrm{TeV}<{M}_{{W}_{R}}<2.4\text{ }\text{ }\mathrm{TeV}$. If the excess is confirmed, it would in general be a direct signal of new physics beyond the Standard Model at the LHC. A TeV scale ${W}_{R}$ would for example not only rule out SU(5) grand unified theory models. It would also imply $B\ensuremath{-}L$ violation at the TeV scale, which would be the first evidence for baryon or lepton number violation in nature, and it has strong implications on the generation of neutrino masses and the baryon asymmetry in the Universe.