Constraints on tan beta in the MSSM from the Upper Bound on the Mass of the Lightest Higgs boson

TL;DR

This paper explores how the upper limit on the lightest Higgs boson mass in the MSSM constrains tan beta, considering theoretical bounds, experimental searches, and the effects of updated calculations and parameter variations.

Contribution

It provides a detailed analysis of how the upper bound on Higgs mass constrains tan beta in the MSSM, including the impact of new two-loop calculations and parameter variations.

Findings

The upper bound on mh increases by several GeV with new two-loop results.

Constraints on tan beta are tightened by combining theoretical bounds with experimental data.

Allowing variations in m_top and M_susy broadens the parameter space for mh.

Abstract

We investigate the possibilities for constraining tan beta within the MSSM by combining the theoretical result for the upper bound on the lightest Higgs-boson mass as a function of tan beta with the informations from the direct experimental search for this particle. We discuss the commonly used ``benchmark'' scenario, in which the parameter values m_top = 175 GeV and M_susy = 1 TeV are chosen, and analyze in detail the effects of varying the other SUSY parameters. We furthermore study the impact of the new diagrammatic two-loop result for mh, which leads to an increase of the upper bound on mh by several GeV, on present and future constraints on tan beta. We suggest a slight generalization of the ``benchmark'' scenario, such that the scenario contains the maximal possible values for mh(tan beta) within the MSSM for fixed m_top and M_susy. The implications of allowing values for m_top, M_susy beyond the ``benchmark'' scenario are also discussed.