Search for neutral Higgs bosons in e+e- collisions at sqrt{s} <= 196 GeV

TL;DR

This paper reports a search for neutral Higgs bosons in electron-positron collisions at energies up to 196 GeV, setting new lower mass limits for the Standard Model and MSSM Higgs bosons based on ALEPH data from 1999.

Contribution

First to analyze ALEPH data at these energies, establishing new lower mass bounds for the Higgs bosons in the Standard Model and MSSM frameworks.

Findings

No evidence for Higgs signal was observed.

95% CL lower mass limit of 98.8 GeV/c^2 for the Standard Model Higgs.

Lower limit of 85.2 GeV/c^2 for the MSSM lightest Higgs boson.

Abstract

A preliminary search for neutral Higgs bosons is performed in the data collected by ALEPH in 1999, corresponding to integrated luminosities of 29.0 and 69.5 pb^-1 at centre-of-mass energies of 191.6 and 195.6 GeV respectively. No evidence for a signal is found. Combined with the lower energy ALEPH data, this observation leads to a 95% confidence level lower mass limit of 98.8 GeV/c^2 for the Standard Model Higgs boson. In the MSSM, the lower limit for the mass of the lightest CP-even Higgs boson h, is found to be 85.2 GeV/c^2 for all values of tan(beta)>=1.