Stellar Light Scattering as a Probe for a Braneworld-Induced Baryogenesis Scenario

TL;DR

This paper explores how a pseudo-scalar boson from a braneworld baryogenesis model could be detected via stellar light scattering, offering a potential observational test for early Universe physics.

Contribution

It introduces a novel phenomenological consequence of a braneworld baryogenesis scenario, proposing a detectable scattering signature of a relic boson around stars.

Findings

Relic boson could form a dark matter component (~0.2%)

One-loop photon coupling leads to a faint halo signature

Potential detection with JWST and future instruments

Abstract

A recent baryogenesis scenario [Phys. Rev. D 110, 023520 (2024)], rooted in a two-brane Universe model, proposed a solution to the matter-antimatter asymmetry through the dynamics of a new pseudo-scalar field. In the present paper, one investigates the phenomenological consequences of this proposal. One shows that the associated boson could persist as a relic from the early Universe, forming a subdominant component of dark matter. While its overall cosmological density is small ($\approx 0.2\%$), one demonstrates that a one-loop process facilitates an ultra-weak coupling to photons, leading to a distinctive scattering signature. One argues that this effect could produce a faint, glowing halo around massive, hot stars, characterized by a unique spectral decay. Detecting or constraining this elusive light with current and future instruments like the JWST would provide a powerful and direct observational test of the underlying braneworld dynamics and its connection to baryogenesis.