Baryon production from embedded metastable strings

Abstract: We quantify the baryon anti-baryon production generated by a metastable cosmic string, similar to the embedded pion string. More precisely, we study skyrmion production mediated by instantons generated by a pion-like metastable string in contact with a thermal bath, and interpret these Skyrmions as baryons. As shown in a previous work, the core of such a metastable string can melt due to quantum tunneling in the charged field direction. The specific configuration of our string containing 4 scalar fields out of equilibrium in contact with a thermal bath is shown to yield skyrmion production with partial or integer winding number. In this work, we describe and quantify this skyrmion production per unit length of the string. We also evaluate the skyrmion-anti skyrmions production by a dense string network by invoking similarity with the Skyrmion production in a phase transition.