Top-quark pole mass in the tadpole-free MS-bar scheme

TL;DR

This paper calculates the top-quark pole mass at full two-loop order in the Standard Model using a tadpole-free MS-bar scheme, providing a gauge-invariant and more stable perturbative result.

Contribution

It introduces a tadpole-free MS-bar scheme for the top-quark pole mass calculation, improving gauge invariance and perturbative stability compared to previous methods.

Findings

Full two-loop order complex pole mass calculated

Elimination of Goldstone boson mass effects via resummation

Analysis of renormalization scale dependence

Abstract

The complex pole mass of the top quark is presented at full two-loop order in the Standard Model, augmenting the known four-loop QCD contributions. The input parameters are the MS-bar Yukawa and gauge couplings, the Higgs self-coupling, and the Higgs vacuum expectation value (VEV). Here, the VEV is defined as the minimum of the full effective potential in Landau gauge, so that tadpoles vanish. This is an alternative to earlier results that instead minimize the tree-level potential, resulting in a VEV that is gauge-fixing independent but accompanied by negative powers of the Higgs self-coupling in perturbative expansions. The effects of non-zero Goldstone boson mass are eliminated by resummation. I also study the renormalization scale dependence of the calculated pole mass.