Search for a light Higgs boson decaying to long-lived weakly-interacting particles in proton-proton collisions at sqrt(s) = 7 TeV with the ATLAS detector

TL;DR

This paper reports a search for a light Higgs boson decaying into long-lived, weakly-interacting particles using ATLAS data, setting limits on such decays due to no observed excess.

Contribution

It introduces a novel search strategy focusing on long-lived particle decays within the muon spectrometer for Higgs bosons in the 120-140 GeV range.

Findings

No excess events observed above background

Limits set on Higgs production times branching ratio

Constraints as a function of particle decay length

Abstract

A search for the decay of a light Higgs (120 - 140 GeV) to a pair of weakly-interacting, long-lived particles in 1.94 fb^-1 of proton-proton collisions at sqrt{s} = 7 TeV recorded in 2011 by the ATLAS detector is presented. The search strategy requires that both long-lived particles decay inside the muon spectrometer. No excess of events is observed above the expected background and limits on the Higgs boson production times branching ratio to weakly-interacting, long-lived particles are derived as a function of the particle proper decay length.