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

TLDR: In this article , the authors presented a search for a right-handed W boson and a heavy neutrino in a final state consisting of two same-flavor leptons (ee or μμ) and two quarks.

Abstract: A bstract A search is presented for a right-handed W boson (W R ) and a heavy neutrino (N), in a final state consisting of two same-flavor leptons (ee or μμ) and two quarks. 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 138 fb − 1 . The search covers two regions of phase space, one where the decay products of the heavy neutrino are merged into a single large-area jet, and one 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. No significant excess over the standard model background expectations is observed. The observations are interpreted as upper limits on the product of W R production cross sections and branching fractions assuming that couplings are identical to those of the standard model W boson. For N masses m N equal to half the W R mass $$ {m}_{{\mathrm{W}}_{\mathrm{R}}} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>m</mml:mi> <mml:msub> <mml:mi>W</mml:mi> <mml:mi>R</mml:mi> </mml:msub> </mml:msub> </mml:math> ( m N = 0 . 2 TeV), $$ {m}_{{\mathrm{W}}_{\mathrm{R}}} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>m</mml:mi> <mml:msub> <mml:mi>W</mml:mi> <mml:mi>R</mml:mi> </mml:msub> </mml:msub> </mml:math> 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. This analysis provides the most stringent limits on the W R mass to date.