First-order Electroweak phase transition at finite density

TL;DR

This paper investigates the Electroweak phase transition at finite temperature and density using effective field theory, reducing theoretical uncertainties and constraining new physics scales, with implications for baryon number preservation.

Contribution

It develops a 2-loop dimensional reduction approach to study the phase transition at finite density, improving theoretical precision and constraining new physics scales.

Findings

Effective reduction of theoretical uncertainty in phase transition parameters.

New physics scale constrained to be below approximately 770-800 GeV.

Chemical potential influences phase transition dynamics and constraints.

Abstract

We study the Electroweak phase transition with the Standard Model effective field theory at finite temperature and finite density. Utilizing the dimensional reduction approach, we construct the tree dimensional thermal effective field theory at finite density and investigate the phase transition dynamics. We evaluate how the results depend on the renormalization scale and the chemical potential. Our results show that, with the tree dimensional thermal effective potential at 2-loop level, we can effectively reduce the theoretical uncertainty in the calculations of the phase transition parameters due to the renormalization scale dependence, and the new physics scale is restricted to be $\Lambda\lesssim (770-800)$ GeV by the baryon number washout avoidance condition. Meanwhile, the presence of the chemical potential would affect the phase transition parameter and make the constraints from the baryon number washout avoidance condition more strict, especially for weaker first-order phase transition scenarios at higher new physics scales.