Searches for Neutral Higgs Bosons in e+e- Collisions around sqrt(s) = 189 GeV

TL;DR

This paper reports on searches for neutral Higgs bosons at around 189 GeV using DELPHI data, setting new lower mass bounds for the Standard Model and MSSM Higgs bosons, and interpreting results within various models.

Contribution

First search results at this energy for neutral Higgs bosons, establishing new mass limits and analyzing implications across multiple theoretical frameworks.

Findings

Standard Model Higgs mass > 94.6 GeV/c^2

MSSM lightest neutral scalar > 82.6 GeV/c^2

MSSM neutral pseudoscalar > 84.1 GeV/c^2

Abstract

Searches for neutral Higgs bosons in the Standard Model and the MSSM have been performed using data collected by the DELPHI experiment at a centre-of-mass energy of 188.7 GeV, corresponding to an integrated luminosity of 158 pb^{-1}. These analyses are used, in combination with our results from lower energies, to set new 95% confidence level lower mass bounds on the Standard Model Higgs boson (94.6 GeV/c^2) and on the lightest neutral scalar (82.6 GeV/c^2) and neutral pseudoscalar (84.1 GeV/c^2) Higgs bosons in a representative scan of the MSSM parameters. The results are also interpreted in the framework of a general two-Higgs doublet model.