Higgs boson searches in CP-conserving and CP-violating MSSM scenarios with the DELPHI detector

TL;DR

This paper reports the final results from DELPHI on Higgs boson searches within the MSSM framework, considering both CP-conserving and CP-violating scenarios, with no significant signals found and limits set on Higgs masses and parameters.

Contribution

It provides the first comprehensive interpretation of DELPHI Higgs search results in MSSM scenarios including CP violation effects.

Findings

No significant excess observed over background expectations.

Excluded regions established for Higgs masses and MSSM parameters.

CP violation reduces experimental sensitivity to Higgs bosons.

Abstract

This paper presents the final interpretation of the results from DELPHI on the searches for Higgs bosons in the Minimal Supersymmetric extension of the Standard Model (MSSM). A few representative scenarios are considered, that include CP conservation and explicit CP violation in the Higgs sector. The experimental results encompass the searches for neutral Higgs bosons at LEP1 and LEP2 in final states as expected in the MSSM, as well as LEP2 searches for charged Higgs bosons and for neutral Higgs bosons decaying into hadrons independent of the quark flavour. The data reveal no significant excess with respect to background expectations. The results are translated into excluded regions of the parameter space in the various scenarios. In the CP-conserving case, these lead to limits on the masses of the lightest scalar and pseudoscalar Higgs bosons, h and A, and on tan(beta). The dependence of these limits on the top quark mass is discussed. Allowing for CP violation reduces the experimental sensitivity to Higgs bosons. It is shown that this effect depends strongly on the values of the parameters responsible for CP violation in the Higgs sector.