Sphaleron without shape mode and its oscillon

TL;DR

This paper demonstrates that oscillons can exhibit a double oscillation structure and decay sphalerons lacking positive energy vibrational modes, with their dynamics effectively modeled by sphaleron collective coordinates.

Contribution

It introduces a novel understanding of oscillon dynamics without shape modes, using sphaleron collective coordinates for modeling.

Findings

Oscillons can have a double oscillation structure.

Decay of sphalerons without positive energy vibrational modes is characterized.

Oscillon dynamics can be captured by sphaleron collective coordinates.

Abstract

We find that an oscillon can possess a characteristic double oscillation structure even though it results in a decay of a sphaleron which does not have any positive energy vibrational mode. We show that dynamics of such an oscillon can still be captured by collective coordinates provided by the sphaleron. Namely, its unstable mode and its scaling deformation i.e., Derrick mode.