A flavour-independent Higgs boson search in e+e- collisions at sqrt(s) up to 209GeV

TL;DR

This paper reports a comprehensive search for the Higgs boson in e+e- collisions at energies up to 209 GeV, setting a lower mass limit of 109.1 GeV for a Standard Model-like Higgs decaying into various final states.

Contribution

It presents a flavor-independent search strategy for the Higgs boson at LEP, extending previous limits by considering all hadronic and tau decay modes regardless of branching ratios.

Findings

No Higgs signal observed within the analyzed data.

Established a 95% confidence level lower mass limit of 109.1 GeV.

The search is independent of the Higgs decay flavor.

Abstract

A search for the Higgsstrahlung process ${\rm e}^+{\rm e}^- \to {\rm HZ}$ is carried out, covering decays of the Higgs boson into any quark pair, a gluon pair or a tau pair. The analysis is based on the $630 {\rm pb}^{-1}$ of data collected by the ALEPH detector at LEP at centre-of-mass energies from 189 to 209 GeV. A 95% C.L. lower mass limit of 109.1\mc2 is obtained for a Higgs boson cross section equal to that expected from the Standard Model if the Higgs boson decays exclusively into hadrons and/or taus, irrespective of the relative branching fractions.