  We present a search for a Higgs boson decaying into a pair of photons based
on 9.6 fb-1 of p-pbar collisions at sqrt(s)=1.96 TeV collected with the D0
detector at the Fermilab Tevatron Collider. The search employs multivariate
techniques to discriminate signal from the non-resonant background and is
separately optimized for a standard model and a fermiophobic Higgs boson. No
significant excess of data above the background prediction is observed and
upper limits on the product of the cross section and branching fraction are
derived at the 95% confidence level as a function of Higgs boson mass. For a
standard model Higgs boson with mass of 125 GeV, the observed (expected) upper
limits are a factor of 12.8 (8.7) above the standard model prediction. The
existence of a fermiophobic Higgs boson with mass in the 100-113 GeV range is
excluded at the 95% confidence level.
