Prospects for and Implications of Measuring the Higgs to Photon-Photon Branching Ratio at the Next Linear $e^+e^-$ Collider

Abstract

We evaluate the prospects for measuring $BR(h\to\gamma\gamma)$ for a Standard-Model-like Higgs boson at the Next Linear $e^+e^-$ Collider in the $e^+e^-\to Z^*\to Z h$ and $e^+e^-\to\nu_e\anti\nu_e h$ production modes. Relative merits of different machine energy/luminosity strategies and different electromagnetic calorimeter designs are evaluated. We emphasize the importance of measuring $BR(h\to\gamma\gamma)$ in order to obtain the total width of a light Higgs boson and thereby the $b\anti b$ partial width that will be critical in discriminating between the SM Higgs and the Higgs bosons of an extended model.