dorsal/arxiv
View SchemaTemperature-Dependent CPT Violation: Constraints from Big Bang Nucleosynthesis
| Authors | Gabriela Barenboim, Anne-Katherine Burns |
|---|---|
| Categories | |
| ArXiv ID | 2601.06259vv1 |
| URL | https://arxiv.org/abs/2601.06259 |
| License | http://creativecommons.org/licenses/by/4.0/ |
Abstract
In this study, we explore temperature-dependent CPT violation during Big Bang Nucleosynthesis (BBN) through electron-positron mass asymmetries parametrized by $b_0(T) = \alpha T^2$. The $T^2$ scaling naturally evades stringent laboratory bounds at zero temperature while allowing for significant CPT violation at MeV scales in the early universe \cite{ParticleDataGroup:2024cfk}. Using a modified version of the BBN code \faGithub \href{https://github.com/vallima/PRyMordial}{\,\texttt{PRyMordial}} with dynamically-solved chemical potentials and appropriate finite-mass corrections, we constrain electron-positron mass differences from observed abundances of Helium-4, Deuterium, and $N_{\rm eff}$. We find that $\alpha$ must be greater than or approximately equal to $10^{-6}$ GeV$^{-1}$ for keV-scale mass differences at BBN. All three observables show no simultaneous $1\sigma$ overlap, though pairwise combinations allow for constrained regions of parameter space. We present three toy models demonstrating how $b_0(T) \propto T^2$ arises from field-theoretic mechanisms, including temperature-driven phase transitions. These results provide the most stringent constraints on early-universe CPT violation in this regime, probing parameter space inaccessible to laboratory experiments.
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"abstract": "In this study, we explore temperature-dependent CPT violation during Big Bang Nucleosynthesis (BBN) through electron-positron mass asymmetries parametrized by $b_0(T) = \\alpha T^2$. The $T^2$ scaling naturally evades stringent laboratory bounds at zero temperature while allowing for significant CPT violation at MeV scales in the early universe \\cite{ParticleDataGroup:2024cfk}. Using a modified version of the BBN code \\faGithub \\href{https://github.com/vallima/PRyMordial}{\\,\\texttt{PRyMordial}} with dynamically-solved chemical potentials and appropriate finite-mass corrections, we constrain electron-positron mass differences from observed abundances of Helium-4, Deuterium, and $N_{\\rm eff}$. We find that $\\alpha$ must be greater than or approximately equal to $10^{-6}$ GeV$^{-1}$ for keV-scale mass differences at BBN. All three observables show no simultaneous $1\\sigma$ overlap, though pairwise combinations allow for constrained regions of parameter space. We present three toy models demonstrating how $b_0(T) \\propto T^2$ arises from field-theoretic mechanisms, including temperature-driven phase transitions. These results provide the most stringent constraints on early-universe CPT violation in this regime, probing parameter space inaccessible to laboratory experiments.",
"arxiv_id": "2601.06259",
"authors": [
"Gabriela Barenboim",
"Anne-Katherine Burns"
],
"categories": [
"hep-ph",
"astro-ph.CO"
],
"license": "http://creativecommons.org/licenses/by/4.0/",
"title": "Temperature-Dependent CPT Violation: Constraints from Big Bang Nucleosynthesis",
"url": "https://arxiv.org/abs/2601.06259",
"version": "v1"
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