Memories of quenches in operator mixing

TL;DR

This paper investigates how sudden quenches in mass and interaction activation in a two-scalar quantum field theory influence operator mixing and can induce phase transitions at late times.

Contribution

It introduces a perturbative analysis of operator mixing effects due to quenches and reveals their impact on the scalar potential and phase transition triggers.

Findings

Late time effective potential is sensitive to quenches.

Operator mixing can trigger phase transitions.

Order of quenches affects the dynamics.

Abstract

We work perturbatively with an interacting quantum field theory comprised of two distinct scalar fields. In this theory, we introduce a sudden quench of the mass of one of the scalars at time $t_0$. Also, the quartic interaction between the two scalars is turned on at time $t_{in}$. These break time-translation invariance. In this setup we examine the effects of the relative ordering of $t_0$ and $t_{in}$ on composite operator mixing. We study how such operator mixing affect features of the scalar potential. We find that the late time effective potential can be sensitive enough to the quenches to trigger phase transitions.