FeynHiggs1.2: Hybrid MSbar/on-shell Renormalization for the CP-even Higgs Boson Sector in the MSSM

TL;DR

This paper presents an updated version of FeynHiggs, a Fortran code for calculating MSSM Higgs boson masses, with improved renormalization schemes that stabilize calculations and slightly increase the predicted lightest Higgs mass.

Contribution

The paper introduces a modified renormalization scheme in FeynHiggs that improves stability and accuracy of Higgs mass predictions in the MSSM.

Findings

Higgs mass calculations are stabilized.

Unphysical threshold effects are reduced.

The lightest Higgs mass increases by 1-2 GeV in most parameter space.

Abstract

An updated version is presented of the Fortran code FeynHiggs for the evaluation of the neutral CP-even Higgs sector masses and mixing angles. It differs from the previous version by a modification of the renormalization scheme concerning the treatment of subleading terms at the one-loop level; the two-loop corrections, for which the leading contributions of O(alpha_t alphas) and O(alpha_t^2) are implemented, are not affected by the modified renormalization prescription. Besides stabilizing the Higgs mass calculations and avoiding unphysically large threshold effects, the mass of the lightest MSSM Higgs boson, m_h, is increased by 1-2 GeV for most parts of the MSSM parameter space.