Speaker
Description
The bubble wall velocity is a key parameter in cosmological first-order phase transitions, affecting both electroweak baryogenesis and gravitational-wave signals. However, it is often treated as an external input in phenomenological studies, while a self-consistent determination remains challenging. In this work, we investigate the bubble wall dynamics in the New Physics Model. The microscopic friction arising from particle interactions with the plasma is evaluated using Boltzmann transport equations, while the macroscopic plasma response is described through hydrodynamic analysis. By applying the steady-state force-balance condition, we numerically determine the bubble wall velocity for different model parameters. We show that the wall velocity is governed by the competition between the driving force from the effective potential and plasma friction, and that its variation can significantly affect the baryon asymmetry. Our study provides a quantitative investigation of bubble wall dynamics in cosmological phase transitions and its implications for early-Universe phenomenology.