Search for Higgs bosons decaying to WW in e+e- collisions at LEP

TL;DR

This paper reports a search for Higgs bosons decaying into WW pairs in electron-positron collisions at LEP, setting new limits on fermiophobic Higgs boson masses with no significant discovery.

Contribution

It introduces a comprehensive search strategy for H -> WW decays at LEP energies and combines results with previous searches to improve mass limits on fermiophobic Higgs bosons.

Findings

No significant evidence for Higgs -> WW decays was observed.

Upper limits on production cross section times branching ratio were established.

Combined analysis extended the mass limits for fermiophobic Higgs bosons.

Abstract

A search for Higgs bosons produced in association with a fermion pair, and decaying to WW, is performed with the data collected by the ALEPH detector at centre-of-mass energies ranging from 191 to 209 GeV. The data correspond to an integrated luminosity of 453.2 pb^-1. Thirteen exclusive selections are developed according to the different final state topologies. No statistically significant evidence for a Higgs boson decaying into a WW pair has been found. An upper limit is derived, as a function of the Higgs boson mass, on the product of the e+e- -> Hff cross section and the H -> WW branching ratio. The data on the search for H -> WW are combined with previously published ALEPH results on the search for H -> gamma gamma, to significantly extend the limits on the mass of a fermiophobic Higgs boson.