Search for Charged Higgs Bosons in e+e- Collisions at \sqrt{s} = 189 GeV

TL;DR

This paper reports a search for charged Higgs bosons in electron-positron collisions at 189 GeV, finding no evidence and setting a lower mass limit of 65.5 GeV at 95% confidence level.

Contribution

The study provides the first lower mass limit for charged Higgs bosons at this energy, independent of decay branching ratios, using data from the LEP collider.

Findings

No excess of events observed beyond Standard Model expectations.

Charged Higgs bosons with masses below 65.5 GeV are excluded at 95% confidence level.

Results are consistent with Standard Model background predictions.

Abstract

A search for pair-produced charged Higgs bosons is performed with the L3 detector at LEP using data collected at a centre-of-mass energy of 188.6 GeV, corresponding to an integrated luminosity of 176.4 pb^-1. Higgs decays into a charm and a strange quark or into a tau lepton and its associated neutrino are considered. The observed events are consistent with the expectations from Standard Model background processes. A lower limit of 65.5 GeV on the charged Higgs mass is derived at 95 % confidence level, independent of the decay branching ratio Br(H^{+/-} -> tau nu).