Two Higgs Doublet Model and Model Independent Interpretation of Neutral Higgs Boson Searches

TL;DR

This paper presents a comprehensive search for neutral Higgs bosons within the Type II Two Higgs Doublet Model, combining data from multiple energies and exploring various decay modes, including flavor-independent channels, to set model-dependent and model-independent limits.

Contribution

It provides the first detailed scan of the 2HDM(II) parameter space with flavor-independent analyses and model-independent limits, enhancing the understanding of Higgs boson decay modes.

Findings

Set new limits on Higgs boson masses and couplings.

Explored decay modes into light quarks and gluons.

Provided model-independent constraints on Higgs production.

Abstract

Searches for the neutral Higgs bosons h0 and A0, are used to obtain limits on the Type II Two Higgs Doublet Model (2HDM(II)) with no CP-violation in the Higgs sector and no additional particles besides the five Higgs bosons. The analysis combines approximately 170 pb-1 of data collected with the OPAL detector at sqrt{s} ~ 189 GeV with previous runs at sqrt{s} ~ mZ and sqrt{s} ~ 183 GeV. The searches are sensitive to the h0, A0 -> qq, gg, tau+tau- and h0 -> A0A0 decay modes of the Higgs bosons. For the first time, the 2HDM(II) parameter space is explored in a detailed scan, and new flavour independent analyses are applied to examine regions in which the neutral Higgs bosons decay predominantly into light quarks or gluons. Model-independent limits are also given.