Kalb-Ramond excitations in a thick-brane scenario with dilaton

TL;DR

This paper analyzes the spectrum of the Kalb-Ramond field in a five-dimensional warped spacetime with a sine-Gordon soliton brane, revealing a tower of massive modes and a zero-mode with potential axion-like properties.

Contribution

It provides a detailed computation of the Kalb-Ramond field spectrum in a non-compact Randall-Sundrum scenario with a sine-Gordon brane, including analytical and numerical results.

Findings

Existence of a zero-mode and massive Kaluza-Klein modes for the Kalb-Ramond field.

Potential connection of low-lying modes to axion-like particles.

Phenomenological implications for the dilaton coupling constant.

Abstract

We compute the full spectrum and eigenstates of the Kalb-Ramond field in a warped non-compact Randall-Sundrum -type five-dimensional spacetime in which the ordinary four-dimensional braneworld is represented by a sine-Gordon soliton. This 3-brane solution is fully consistent with both the warped gravitational field and bulk dilaton configurations. In such a background we embed a bulk antisymmetric tensor field and obtain, after reduction, an infinite tower of normalizable Kaluza-Klein massive components along with a zero-mode. The low lying mass eigenstates of the Kalb-Ramond field may be related to the axion pseudoscalar. This yields phenomenological implications on the space of parameters, particularly on the dilaton coupling constant. Both analytical and numerical results are given.