Discovery prospects of an almost fermiophobicW′in the three-site Higgsless model at the LHC

Abstract

In extensions of the standard model with compactified extra dimensions, perturbative unitarity of the longitudinal gauge bosons is maintained through the contribution of heavy Kaluza-Klein excitations of the gauge fields, without the necessity of introducing a Higgs field. The three-site Higgsless model represents a minimal approach in this respect, containing just one extra set of heavy gauge bosons ${Z}^{\ensuremath{'}}/{W}^{\ensuremath{'}\ifmmode\pm\else\textpm\fi{}}$ in the spectrum. While the ${Z}^{\ensuremath{'}}$ can have robust couplings to SM fermions and, hence, may be detected within the first $1--20\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of LHC data ($\sqrt{s}=14\text{ }\text{ }\mathrm{TeV}$), the coupling of the ${W}^{\ensuremath{'}}$ to light fermions is suppressed and depends on the model parameters. Expanding on previous parton-level studies, we determine discovery thresholds of the ${W}^{\ensuremath{'}}$ in $s$-channel Drell-Yan production at the LHC for masses ${m}_{{W}^{\ensuremath{'}}}=380$, 500, and 600 GeV, combining analyses of the semileptonic final states $\ensuremath{\ell}\ensuremath{\ell}jj$, $\ensuremath{\ell}\ensuremath{\nu}jj$ and the leptonic final state $\ensuremath{\ell}\ensuremath{\nu}\ensuremath{\ell}\ensuremath{\ell}$ ($\ensuremath{\ell}=e,\ensuremath{\mu}$) including fast detector simulation.