1212.1723 (Johanna Karouby)

Instanton in a thermal bath and melting of a pion string    [PDF]

Johanna Karouby

The instanton production for out-of-equilibrium scalar fields in a thermal bath of photons is computed in the thin-wall limit. Such a process accurately describes the melting and the breaking of a pion string via bubble nucleation. In a plasma, the topologically unstable pion string becomes metastable so that it can decay through quantum tunneling. In the following, the decay of the false vacuum into the true vacuum in the core of the string is used to quantify the quantum decay rate of the string into two strings. The cylindrically and spherically symmetric instantons are found. As a result of the tunneling, the string core melts, vacuum bubbles propagate along the string at almost the speed of light and baryon production could occur via skyrmion production.

View original: http://arxiv.org/abs/1212.1723