Spontaneous CP Violation at Finite Temperature in the MSSM

By studying the effective potential of the MSSM at finite temperature, we find that CP can be spontaneously broken in the intermediate region between the symmetric and broken phases separated by the bubble wall created at the phase transition. If CP is violated in this manner, there could be a bubble wall connecting CP conserving vacua and violating CP halfway, which would result in sufficient baryon asymmetry of the universe.