Scattering of the $\varphi^8$ kinks with power-law asymptotics

TL;DR

This paper investigates the scattering behavior of $$ kinks with power-law asymptotics, revealing long-range interactions and escape windows due to resonant energy exchange, supported by spectral analysis.

Contribution

It provides the first detailed analysis of $$ kink scattering with power-law tails, highlighting long-range effects and resonance phenomena not previously studied.

Findings

Identification of long-range interactions due to power-law tails

Observation of escape windows in kink-antikink scattering

Spectral analysis of kink and composite configurations

Abstract

We study the scattering of the $\varphi^8$ kinks off each other, namely, we consider those $\varphi^8$ kinks that have power-law asymptotics. The slow power-law fall-off leads to a long-range interaction between the kink and the antikink. We investigate how the scattering scenarios depend on the initial velocities of the colliding kinks. In particular, we observe the `escape windows' -- the escape of the kinks after two or more collisions, explained by the resonant energy exchange between the translational and vibrational modes. In order to elucidate this phenomenon, we also analyze the excitation spectra of a solitary kink and of a composite kink+antikink configuration.