Nucleosynthesis Constraints on a Scale-Dependent New Intermediate Range Interaction

TL;DR

This paper constrains a new intermediate-range baryon-coupled interaction using primordial nucleosynthesis data, finding limits on its strength and exploring implications for dark matter and interstellar medium ionization.

Contribution

It provides the first detailed constraints on a scale-dependent new interaction from nucleosynthesis and discusses its potential role in dark matter and cosmic ionization.

Findings

Standard nucleosynthesis limits the interaction strength to $eta_5 \\lesssim 0.2$ for ranges > 1 m.

The scalar particle could be a dark matter component affecting interstellar ionization.

Implications for Lyman-$\\alpha$ cloud temperatures are considered.

Abstract

We derive constraints on the strength of a new intermediate range interaction that couples to baryon number from primordial nucleosynthesis yields. The nucleosysnthesis limits here used arise from matching observations and predictions of standard and inhomogeneous primordial scenarios. We show that the standard nucleosynthesis scenario is more restrictive ($\alpha_5 \lsim 0.2$) when the range of the interaction is greater than about 1 m. We further discuss the implications of considering the scalar particle responsible for the new interaction as the main component of the dark matter in the galactic halo such that its decay can account for the ionization of hydrogen in the interstellar medium and the temperature of Lyman-$\alpha$ clouds.