Abstract

Higgs bosons with very suppressed couplings to fermions ("fermiophobic Higgs bosons," hf) can decay to two photons (γγ) with a branching ratio significantly larger than that expected for the standard model Higgs boson for mhf<150GeV. Such a particle would give a clear signal at the LHC and can arise in the two Higgs doublet model (type I) in which hf→γγ is mediated by W± and charged Higgs boson (H±) loops. We show that the H± loops can cause both constructive and destructive contributions with a magnitude considerably larger than the anticipated precision in the measurement of the photonic decay channel at future hadron and lepton colliders. © 2007 The American Physical Society.