Refinements of the Bottom and Strange MSSM Higgs Yukawa Couplings at NNLO

TL;DR

This paper refines the calculation of bottom and strange Yukawa couplings in the MSSM at NNLO, including subleading effects and electroweak contributions, reducing theoretical uncertainties to about one percent.

Contribution

It extends previous two-loop calculations by incorporating subleading terms and electroweak effects, providing more precise Yukawa coupling predictions in the MSSM.

Findings

Residual uncertainties are reduced to about 1%.

Includes subleading corrections related to $A_b$ and electroweak effects.

Provides improved theoretical predictions for MSSM Yukawa couplings.

Abstract

We extend the already existing two-loop calculation of the effective bottom-Yukawa coupling in the MSSM. In addition to the resummation of the dominant corrections for large values of tg$\beta$, we include the subleading terms related to the trilinear Higgs coupling $A_b$ and contributions induced by the electroweak gauge couplings. This calculation has been extended to the NNLO corrections to the MSSM strange-Yukawa coupling. Our analysis leads to residual theoretical uncertainties of the effective Yukawa couplings at the per-cent level.