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 $Z^{\prime }/W^{\prime \pm }$ in the spectrum. While the $Z^{\prime }$ can have robust couplings to SM fermions and, hence, may be detected within the first $1–20{\mathrm{fb}}^{-1}$ of LHC data ($\sqrt{s}=14\mathrm{TeV}$), the coupling of the $W^{\prime }$ to light fermions is suppressed and depends on the model parameters. Expanding on previous parton-level studies, we determine discovery thresholds of the $W^{\prime }$ in $s$-channel Drell-Yan production at the LHC for masses $m_{W^{\prime }}=380$, 500, and 600 GeV, combining analyses of the semileptonic final states $\ell \ell jj$, $\ell \nu jj$ and the leptonic final state $\ell \nu \ell \ell$ ($\ell =e,\mu$) including fast detector simulation.

• Received 8 November 2011

DOI:https://doi.org/10.1103/PhysRevD.85.015002