Search for the Standard Model Higgs Boson in e+e- Collisions at sqrt(s) = 192-209 GeV

TL;DR

This paper reports a search for the Standard Model Higgs boson using data from the OPAL detector at LEP, setting a lower mass limit of 109.7 GeV at 95% confidence level based on collisions at 192-209 GeV.

Contribution

First comprehensive search for the Higgs boson in this energy range using OPAL data, establishing a new lower mass bound.

Findings

No significant excess observed over background

Lower mass limit of 109.7 GeV at 95% confidence level

Data consistent with background and potential signals at higher masses

Abstract

A search for the Standard Model Higgs boson has been performed with the OPAL detector at LEP based on the full data sample collected at sqrt(s) = 192-209 GeV in 1999 and 2000, corresponding to an integrated luminosity of approximately 426 pb-1. The data are examined for their consistency with the background-only hypothesis and various Higgs boson mass hypotheses. A lower bound of 109.7 GeV is obtained on the Higgs boson mass at the 95% confidence level. At higher masses, the data are consistent with both the background and the signal-plus-background hypotheses.