On the wall velocity dependence of electroweak baryogenesis

We re-evaluate the status of supersonic electroweak baryogenesis using a generalized fluid Ansatz for the non-equilibrium distribution functions. Instead of truncating the expansion to first order in momentum, we allow for higher order terms as well, including up to 21 fluctuations. The collision terms are computed analytically at leading-log accuracy. We also point out inconsistencies in the standard treatments of transport in electroweak baryogenesis, arguing that one cannot do without specifying an Ansatz for the distribution function. We present the first analysis of baryogenesis using the fluid approximation to higher orders. Our results support the recent findings that baryogenesis may indeed be possible even in the presence of supersonic wall velocities.

Automated summary

This study re-evaluates the status of supersonic electroweak baryogenesis using a generalized fluid Ansatz for non-equilibrium distribution functions. By allowing for higher order terms and pointing out inconsistencies in standard treatments of transport, it suggests that baryogenesis may be possible even in the presence of supersonic wall velocities. The analysis supports recent findings and presents the first analysis of baryogenesis using the fluid approximation to higher orders.