Braneworld Baryogenesis and QCD-Era Magnetogenesis: A Predictive Link

TL;DR

This paper links primordial magnetic fields to braneworld baryogenesis, showing that realistic QCD-era magnetogenesis can produce the observed matter-antimatter asymmetry and influence large-scale baryon density fluctuations.

Contribution

It demonstrates a predictive connection between primordial magnetic fields and braneworld baryogenesis, incorporating realistic QCD-era magnetogenesis into the model.

Findings

Magnetic fields of order 10^{10} T are needed after the quark-hadron transition.

Magnetic fluctuations induce a white noise baryon-density spectrum on large scales.

The model's predictions are consistent with CMB constraints on isocurvature modes.

Abstract

We demonstrate that primordial magnetic fields (PMF) play a decisive role in the braneworld baryogenesis scenario of [Phys. Rev. D $\textbf{110}$, 023520 (2024)], where C/CP violation arises from the coupling of visible and hidden matter-antimatter sectors through a pseudo-scalar field. Although this mechanism generates baryon number efficiently only after the quark-hadron transition, by incorporating a realistic stochastic PMF within a semi-analytical framework, we find that matching the observed baryon-antibaryon asymmetry robustly requires PMF strengths of order $10^{10}$ T right after the transition, in agreement with causal QCD-era magnetogenesis. We further reveal that magnetic fluctuations drive the baryon-density spectrum to white noise on large scales, yielding an isocurvature component compatible with Cosmic Microwave Background (CMB) bounds. This establishes a predictive link between the braneworld baryogenesis model and realistic early-Universe magnetic fields.