Studies of Strong Electroweak Symmetry Breaking at Photon Colliders

Abstract

It has recently been shown that the studies of strongly-interacting electroweak symmetry breaking (EWSB) at photon colliders, via photon splitting into $W$ pair followed by longitudinal $W$-boson scattering, could be possible. Here we present a signal-background analysis for the scattering channels $W^+_L W^-_L \to Z_L Z_L$ and $W^+_L W^-_L \to W^+_L W^-_L$ with background coming from the standard model (SM) production of $\gamma\gamma \to WW ZZ$ and $WWWW$, respectively. We illustrate the analysis using the SM with a heavy Higgs boson $(m_H\approx 1$ TeV) to represent a typical strongly-interacting EWSB model and the SM with a light Higgs boson ($m_H\approx 0.1$ TeV) to represent the background. We come up with a set of kinematic acceptance to enhance the signal-to-background ratio. Extension of the kinematic acceptance to other strongly-interacting EWSB models is then trivial, and the signal cross sections for various EWSB models are calculated. We found that it is very feasible to probe the EWSB sector at a photon collider of center-of-mass energy of 2 TeV with a luminosity of just 10~fb$^{-1}$.