Electroweak Baryogenesis with a Pseudo-Goldstone Higgs

TL;DR

This paper investigates electroweak baryogenesis within a pseudo-Goldstone Higgs framework, demonstrating that new physics can enable a strong first-order phase transition and enhanced CP violation, crucial for baryon asymmetry generation.

Contribution

It introduces a detailed analysis of the electroweak phase transition considering dimension six operators in a pseudo-Goldstone Higgs model, improving the perturbative treatment of thermal effects.

Findings

New physics allows a sufficiently first-order electroweak phase transition.

Enhanced CP violation effects are possible due to the model.

Improved calculation of gauge boson thermal masses impacts phase transition analysis.

Abstract

We examine the nature of electroweak Baryogenesis when the Higgs boson's properties are modified by the effects of new physics. We utilize the effective potential to one loop (ring improving the finite temperature perturbative expansion) while retaining parametrically enhanced dimension six operators of O(v^2/f^2) in the Higgs sector. These parametrically enhanced operators would be present if the Higgs is a pseudo-goldstone boson of a new physics sector with a characteristic mass scale Lambda ~ TeV, a coupling constant (4 pi) > g > 1 and a strong decay constant scale f = Lambda/g. We find that generically the effect of new physics of this form allows a sufficiently first order electro-weak phase transition so that the produced Baryon number can avoid washing out, and has enhanced effects due to new sources CP violation. We also improve the description of the electroweak phase transition in perturbation theory by determining the thermal mass eigenstate basis of the standard model gauge boson fields. This improves the calculation of the finite temperature effects through incorporating mixing in the determination of the vector boson thermal masses of the standard model. These effects are essential to determining the nature of the phase transition in the standard model and are of interest in our Pseudo-Goldstone Baryogenesis scenario.