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arXiv · 2603.02652

Weinberg Angle, Neutron Abundance in BBN, and Lifetime

Cheng Tao Yang·Johann Rafelski
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Abstract

We present state of the art kinetic theory determination of the neutron abundance available for the Big-Bang nucleosynthesis (BBN). Our work is motivated by the study of the neutron lifespan measured in the laboratory and the unknown strength of weak interactions coupling constant $G_\mathrm{F}$ at finite temperature in the primordial Universe. We draw attention to the relevant dependence of $G_\mathrm{F}$ on the symmetry breaking Weinberg angle $s^2_\mathrm{W}$, a free parameter in the standard model of particle physics. We establish how the value of $s^2_\mathrm{W}$ by way of $G_\mathrm{F}$ modification influences neutron abundance available for BBN and neutron lifetime.

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Cheng Tao Yang, Johann Rafelski. 2026-03-03. Weinberg Angle, Neutron Abundance in BBN, and Lifetime. https://doi.org/10.3390/particles9030068

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