Bounce solutions and the transition to thermal hopping in phi^4 theory with a phi^3 term

TL;DR

This paper investigates the transition from quantum tunneling to thermal hopping in a scalar field theory with cubic symmetry breaking, using numerical bounce solutions to analyze the nature of the transition.

Contribution

It introduces a numerical method to find bounce solutions in a phi^4 theory with a phi^3 term and characterizes the order of the transition based on symmetry-breaking strength.

Findings

Transition is first-order for small symmetry-breaking coupling f.

Transition remains first-order, but weakly, for higher values of f.

Numerical bounce solutions interpolate between zero-temperature and high-temperature regimes.

Abstract

The nature of the transition from quantum tunneling at low temperatures to thermal hopping at high temperatures is investigated in a scalar field theory with cubic symmetry breaking. The bounce solution which interpolates between the zero-temperature and high-temperature solutions is obtained numerically, using a multigrid method. It is found that, for a small value of the symmetry-breaking coupling f, the transition is first-order. For higher values of f, the transition continues to be first-order, though weakly so.