Two-loop matching of renormalizable operators: general considerations and applications

TL;DR

This paper advances the understanding of two-loop matching conditions for renormalizable operators in effective field theories, providing detailed diagrammatic analysis and concrete applications to models like the MSSM.

Contribution

It offers a detailed diagrammatic approach to two-loop operator matching and applies it to improve Higgs mass predictions in supersymmetric models.

Findings

Derived two-loop matching conditions for scalar couplings.

Compared different methods for calculating matching conditions.

Improved Higgs mass prediction in MSSM using the new formulas.

Abstract

Low-energy effective field theories (EFT) encode information about the physics at high energies--i.e., the high-energy theory (HET). To extract this information the EFT and the HET have to be matched to each other. At the one-loop level, general results for the matching of renormalizable operators have already been obtained in the literature. In the present paper, we take a step towards a better understanding of renormalizable operator matching at the two-loop level: Focusing on the diagrammatic method, we discuss in detail the various contributions to two-loop matching conditions and compare different approaches to derive them. Moreover, we discuss which observables are best suited for the derivation of matching conditions. As a concrete application, we calculate the $\mathcal{O}\left(\alpha_t \alpha_s \right)$ and $\mathcal{O} \left(\alpha_t^2 \right)$ matching conditions of the scalar four-point couplings between the Standard Model (SM) and the Two-Higgs-Doublet Model (THDM) as well as the THDM and the Minimal Supersymmetric Standard Model (MSSM). We use the derived formulas to improve the prediction of the SM-like Higgs mass in the MSSM using the THDM as EFT.