Higgs Physics with a gamma gamma Collider Based on CLIC 1

Abstract

We present the machine parameters and physics capabilities of the CLIC Higgs Experiment (CLICHE), a low-energy $\gamma\gamma$ collider based on CLIC 1, the demonstration project for the higher-energy two-beam accelerator CLIC. CLICHE is conceived as a factory capable of producing around 20,000 light Higgs bosons per year. We discuss the requirements for the CLIC 1 beams and a laser backscattering system capable of producing a $\gamma\gamma$ total (peak) luminosity of $2.0 (0.36) \times 10^{34}$ cm$^{-2}$s$^{-1}$ with $E_{CM}(\gamma \gamma) \sim 115$ GeV. We show how CLICHE could be used to measure accurately the mass, $\bar b b$, $WW$ and $\gamma \gamma$ decays of a light Higgs boson. We illustrate how these measurements may distinguish between the Standard Model Higgs boson and those in supersymmetric and more general two-Higgs-doublet models, complementing the measurements to be made with other accelerators. We also comment on other prospects in $\gamma\gamma$ and $e^- \gamma$ physics with CLICHE.