Search for a right-handed W boson and a heavy neutrino in proton-proton collisions at $\sqrt{s}$ = 13 TeV



A search for a right-handed $\mathrm{W}$ boson ($\mathrm{W_R}$) and a heavy neutrino ($\mathrm{N}$), in a final state consisting of two same--flavor leptons ($\mathrm{e}\mathrm{e}$ or $\mu\mu$) and two quarks, is presented. The search is performed with the CMS experiment at the CERN LHC using a data sample of proton-proton collisions at a center-of-mass energy of 13 TeV corresponding to an integrated luminosity of 137 $\mathrm{fb}^{-1}$. The search covers both regions of phase space where the decay products of the heavy neutrino are merged into a single large-area jet and where the decay products are well separated. The expected signal is characterized by an excess in the invariant mass distribution of the final-state objects and no significant excess over the standard model background expectations is observed. The observations are interpreted as upper limits on the product of $\mathrm{W_R}$ production cross sections and branching fractions assuming that couplings are identical to those of the standard model $\mathrm{W}$ boson. For $m_{\mathrm{N}}=1/2~m_{\mathrm{W_R}}$ ($m_{\mathrm{N}}=200$ GeV), the mass of the $\mathrm{W_R}$ is excluded at 95\% confidence level up to 4.7 (4.8) and 5.0 (5.4) TeV for the electron and muon channels, respectively. The maximum observed global significance is in the electron channel and correpsonds to 2.78 standard deviations for a signal with $(m_{\mathrm{W_R}}, m_{\mathrm{N}}) = (6.0, 0.8)$ TeV. This analysis provides the most stringent limits on the $\mathrm{W_R}$ mass to date.
Date made available21 Feb 2022


  • hep-ex


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