The Standard Model Higgs in $\gamma \gamma$ Collisions

Abstract

For a Higgs boson below the $W^{\pm }$ threshold, the $\gamma \gamma$ collider option of a future linear $e^{+}{e}^{-}$ machine is compelling. In this case one can measure the ``gold-plated'' loop induced $\Gamma (H⟶\gamma \gamma )$ partial width to high precision, testing various extensions of the Standard Model. With recent progress in the expected $\gamma \gamma$ luminosity at TESLA, we find that for a Higgs of 115 GeV a statistical accuracy of the two photon partial width of 1.4 % is possible. The total width depends thus solely on the accuracy of $BR(H⟶\gamma \gamma )$ and is of $\mathcal{O}(10$.

contribution to LCWS2000 at Fermilab