Primordial nucleosynthesis as a probe of fundamental physics parameters

TL;DR

This paper systematically investigates how variations in fundamental physical constants influence primordial element abundances, providing insights into early universe physics and potential links to particle physics parameters.

Contribution

It establishes the response of primordial nucleosynthesis to multiple nuclear physics parameters and connects these to fundamental Standard Model parameters, including grand unification relations.

Findings

Strong dependence of 4He on n-p mass difference

Deuterium abundance sensitive to nucleon mass

7Li abundance strongly depends on light quark mass

Abstract

We analyze the effect of variation of fundamental couplings and mass scales on primordial nucleosynthesis in a systematic way. The first step establishes the response of primordial element abundances to the variation of a large number of nuclear physics parameters, including nuclear binding energies. We find a strong influence of the n-p mass difference (for the 4He abundance), of the nucleon mass (for deuterium) and of A=3,4,7 binding energies (for 3He, 6Li and 7Li). A second step relates the nuclear parameters to the parameters of the Standard Model of particle physics. The deuterium, and, above all, 7Li abundances depend strongly on the average light quark mass hat{m} \equiv (m_u+m_d)/2. We calculate the behaviour of abundances when variations of fundamental parameters obey relations arising from grand unification. We also discuss the possibility of a substantial shift in the lithium abundance while the deuterium and 4He abundances are only weakly affected.