Two-loop QCD corrections to the MSSM Higgs masses beyond the effective-potential approximation

TL;DR

This paper calculates two-loop QCD corrections to MSSM Higgs masses, including external momentum effects, providing more accurate predictions that are relevant for current LHC measurements.

Contribution

It presents the first complete calculation of two-loop QCD corrections with external momenta in the MSSM Higgs sector, clarifying previous inconsistencies.

Findings

Corrections of order alpha_t*alpha_s and alpha*alpha_s are computed.

Numerical impact on Higgs mass predictions is moderate but significant.

Comparison with previous results reveals an inconsistency in recent calculations.

Abstract

We compute the two-loop QCD corrections to the neutral Higgs-boson masses in the MSSM, including the effect of non-vanishing external momenta in the self-energies. We obtain corrections of O(alpha_t*alpha_s) and O(alpha*alpha_s), i.e., all two-loop corrections that involve the strong gauge coupling when the only non-vanishing Yukawa coupling is the top one. We adopt either the DRbar renormalization scheme or a mixed OS-DRbar scheme where the top/stop parameters are renormalized on-shell. We compare our results with those of earlier calculations, pointing out an inconsistency in a recent result obtained in the mixed OS-DRbar scheme. The numerical impact of the new corrections on the prediction for the lightest-scalar mass is moderate, but already comparable to the accuracy of the Higgs-mass measurement at the LHC.