Higgs Decay to Photons at Two Loops
  The calculation of the two-loop corrections to the partial width of an intermediate-mass Higgs boson decaying into a pair of photons is reviewed. The main focus lies on the electroweak (EW) contributions. The sum of the EW corrections ranges from -4% to 0% for a Higgs mass between 100 GeV and 150 GeV, while the complete correction at two-loop order amounts to less than +-1.5% in this regime. 
Frank Fugel (Hamburg U., Inst. Theor. Phys. II)