Search for a Neutral Gauge Boson with Nonuniversal Fermion Couplings in Vector Boson Fusion Processes in Proton-Proton Collisions at $ \sqrt{s}=13\text{}\text{}\mathrm{TeV}$

The first search for a heavy neutral spin-1 gauge boson ($ {Z}^{\prime }$) with nonuniversal fermion couplings produced via vector boson fusion processes and decaying to tau leptons or $ W$ bosons is presented. The analysis is performed using LHC data at $ \sqrt{s}=13\text{}\text{}\mathrm{TeV}$, collected from 2016 to 2018 with the CMS experiment and corresponding to an integrated luminosity of $ 138\text{}\text{}{\mathrm{fb}}^{-1}$. The data are consistent with the standard model predictions. Upper limits are set on the product of the cross section for production of the $ {Z}^{\prime }$ boson and its branching fraction to $ \tau \tau $ or $ WW$. The presence of a $ {Z}^{\prime }$ boson decaying to $ {\tau }^{+}{\tau }^{-}$ ($ {W}^{+}{W}^{-}$) is excluded for masses up to 2.45(1.60) TeV, depending on the $ {Z}^{\prime }$ boson coupling to standard model weak bosons, and assuming a $ {Z}^{\prime }\to {\tau }^{+}{\tau }^{-}$ ($ {W}^{+}{W}^{-}$) branching fraction of 50%.