Search for a Higgs Boson Decaying into Two Photons in e+e- Interactions at sqrt{s}=189GeV

TL;DR

This paper reports a search for a Higgs boson decaying into two photons in electron-positron collisions at 189 GeV, setting limits on the decay and mass of a fermiophobic Higgs boson.

Contribution

It provides the first experimental limits on the Higgs to two photons decay mode at this energy, including a lower mass bound for a fermiophobic Higgs.

Findings

No signal observed for Higgs decaying into two photons.

Set a lower mass limit of 94.9 GeV for a fermiophobic Higgs.

Derived limits on the Higgs decay branching fraction as a function of mass.

Abstract

A search is performed for a Higgs boson produced in association with a Z boson and decaying into two photons, using the L3 data collected at LEP at a centre-of-mass energy of 189 GeV. All decay modes of the Z are considered. No signal is observed and limits on the branching fraction of the Higgs boson decay into two photons as a function of the Higgs mass are derived assuming a Standard Model production rate. A lower limit on the mass of a fermiophobic Higgs is set at 94.9 GeV at 95% confidence level.