LHC Signatures of New Gauge Bosons in the Minimal Higgsless Model

Abstract

We study the LHC signatures of new gauge bosons in the gauge-invariant minimal Higgsless model. It predicts an extra pair of W_1 and Z_1 bosons which can be as light as ~400GeV and play a key role in the delay of unitarity violation. We analyze the W_1 signals in pp --> W_0Z_0Z_0 --> jj4\ell and pp --> jj W_0Z_0 --> jj3\ellνprocesses at the LHC, including the complete electroweak and QCD backgrounds. We reveal the complementarity between these two channels for discovering the W_1 boson, and demonstrate the LHC discovery potential over the full range of allowed W_1 mass.

Figures (4)

• Figure 1: Signal and background events in the process $pp\to W_1^{(\ast)}Z_0 \to W_0Z_0Z_0\to jj\,\ell^+\ell^-\ell^+\ell^-$ for an integrated luminosity of 100 fb$^{-1}$.
• Figure 2: Invariant-mass distribution $M_{W_0Z_0}$ in $pp\to W_0Z_0qq'$ for $M_{W_1}=500$ GeV: (a). fusion (dashed) and non-fusion (solid) contributions in the unitary gauge, fusion (densed-dashed) and non-fusion (dashed-dotted) contributions in the 't Hooft-Feynman gauge, and the sum of fusion and non-fusion contributions in both gauges which coincide (dotted); (b). comparison of the summed contributions (after cancellation) between the two gauges, in the MHLM; (c). same as (b), but for a toy model based on a sum-rule approach (like that in Ref. mat) which explicitly violates gauge-invariance.
• Figure 3: Numbers of signal and background events versus the transverse mass $M_T(W_0Z_0)$ after imposing the cuts (\ref{['oldcuts']})-(\ref{['newcuts-lepton']}) for an integrated luminosity of 100 fb$^{-1}$.
• Figure 4: Integrated luminosities required for $3\sigma$ and $5\sigma$ detection of $W_1$ signals as a function of $M_{W_1}$. The dotted and dashed-dotted curves are for the $W_0Z_0Z_0$ channel, while the dashed and solid curves are for the $W_0Z_0jj$ channel.