Confinement and stability of the motion of test particles in thick branes

TL;DR

This paper demonstrates that stable confinement of test particles in a thick brane can be achieved through a direct scalar field interaction, extending the understanding of particle dynamics in braneworld models.

Contribution

It introduces a Yukawa-type interaction in the particle Lagrangian to enable stable confinement in thick branes, addressing a limitation of gravity-only confinement.

Findings

Stable confinement is possible with scalar field interaction.

Gravity alone cannot confine particles in thick branes.

Modified Lagrangian enables particle stability in the brane.

Abstract

We consider the motion of test particles in a thick brane version of Randall-Sundrum type II model. It is known that gravity alone cannot explain the confinement of test particles in this kind of brane. In this paper we show that a stable confinement in a domain wall is possible by admitting a direct interaction between test particles and a scalar field. This interaction is implemented by a modification of the Lagrangian of the particle which is inspired by a Yukawa-type interaction between fermions and scalar fields.