Search for gammagamma decays of a Higgs boson produced in association with a fermion pair in e+e- collisions at centre-of-mass energies up to 209 GeV

The analysis of photon pair events arising from a Higgs boson produced in association with a fermion pair via the Higgs-strahlung process e+e- -> Hff, with ff=nu/nu, e+e-,mu+/mu-,tau+/tau- or qq is performed in the data sample collected at LEP with the ALEPH detector at centre-of-mass energies up to 209 GeV. One event is selected in the data, while 2.8 events are expected from standard model processes. An upper limit on the product of the e+e- -> Hff cross section and the H->gamma/gamma branching fraction as a function of the Higgs boson mass is derived and combined with previous results obtained at lower energies. In particular, a fermiophobic Higgs boson produced with the standard model cross section is excluded at 95% confidence level for all masses below 106.4 GeV/c**2.