Anomalous gauge couplings of the Higgs boson at high energy photon colliders

beyond the standard model (SM) and SM backgrounds are carefully studied. We propose certain kinematic cuts to suppress the standard model backgrounds. For an integrated luminosity of 1 ab, we show that (a) γγ → ZZ can provide a test of gHγγ to the 3σ sensitivity of O(10 − 10) TeV at a 500 GeV ILC, and O(10) TeV at a 1 TeV ILC and a 3 TeV CLIC, and (b) γγ → WWWW at a 3 TeV CLIC can test all the anomalous couplings gHV V ’s to the 3σ sensitivity of O(10 −3 − 10) TeV.