Renormalization scheme dependence of the two-loop QCD corrections to the neutral Higgs-boson masses in the MSSM

TL;DR

This paper investigates the dependence of two-loop QCD corrections to the MSSM Higgs-boson mass on the renormalization scheme, clarifying discrepancies between recent calculations and providing a consistent implementation in FeynHiggs.

Contribution

It identifies the source of differences in two-loop corrections as the renormalization of the top-quark mass and compares on-shell and DRbar schemes for improved accuracy.

Findings

Differences in results are due to top-quark mass renormalization schemes.

The DRbar scheme implementation is added to FeynHiggs.

The study confirms the consistency of recent two-loop correction calculations.

Abstract

Reaching a theoretical accuracy in the prediction of the lightest MSSM Higgs-boson mass, M_h, at the level of the current experimental precision requires the inclusion of momentum-dependent contributions at the two-loop level. Recently two groups presented the two-loop QCD momentum-dependent corrections to Mh [1,2], using a hybrid on-shell--DRbar scheme, with apparently different results. We show that the differences can be traced back to a different renormalization of the top-quark mass, and that the claim in [2] of an inconsistency in [1] is incorrect. We furthermore compare consistently the results for M_h obtained with the top-quark mass renormalized on-shell and DRbar. The latter calculation has been added to the FeynHiggs package and can be used to estimate missing higher-order corrections beyond the two-loop level.