Phenomenology of electroweak bubbles and gravitational waves in the Littlest Higgs Model with T parity

TL;DR

This paper investigates the dynamics of electroweak bubbles during a strong first-order phase transition in the Littlest Higgs model with T parity, analyzing bubble expansion and gravitational wave production.

Contribution

It provides a detailed analysis of bubble dynamics and gravitational wave generation in a specific beyond Standard Model scenario with a strong phase transition.

Findings

Bubbles expand due to higher pressure inside the symmetric phase.

Bubble walls exhibit supersonic deflagrated motion.

Gravitational waves are generated from bubble collisions and plasma turbulence.

Abstract

We study the dynamics of electroweak bubbles in the scenario of a strong first order inverse electroweak phase transition at the TeV scale involving the global structure of the nonlinear sigma field in the littlest Higgs model with T parity. Employing the one-loop order finite temperature effective potential, we find that the pressure in the symmetric phase i.e., inside the bubble is always greater than that in the asymmetric phase i.e., outside the bubble, so that the bubbles are expanding. By calculating the fluid velocities in the two phases we arrive at the condition of a supersonic deflagrated motion of the bubble walls. We then discuss the generation of gravitational waves from the collisions of such bubbles as well as from the turbulence of the plasma.