Big Bang Nucleosynthesis with long-lived strongly interacting relic particles

TL;DR

This paper investigates how long-lived strongly interacting relic particles could have influenced big bang nucleosynthesis, potentially leading to the formation of heavy elements and leaving signatures on primordial light element abundances.

Contribution

It introduces a detailed model of relic X particles affecting BBN, including reaction rates and constraints on their abundance based on observed primordial element levels.

Findings

X particles form bound states with nuclei early in BBN

Constraints exclude models with long-lived colored particles over 200 seconds

Potential production of 9Be and 10B as signatures of X particles

Abstract

We study effects of relic long-lived strongly interacting massive particles (X particles) on big bang nucleosynthesis (BBN). The X particle is assumed to have existed during the BBN epoch, but decayed long before detected. The interaction strength between an X and a nucleon is assumed to be similar to that between nucleons. Rates of nuclear reactions and beta decay of X-nuclei are calculated, and the BBN in the presence of neutral charged X^0 particles is calculated taking account of captures of X^0 by nuclei. As a result, the X^0 particles form bound states with normal nuclei during a relatively early epoch of BBN leading to the production of heavy elements. Constraints on the abundance of X^0 are derived from observations of primordial light element abundances. Particle models which predict long-lived colored particles with lifetimes longer than about 200 s are rejected. This scenario prefers the production of 9Be and 10B. There might, therefore, remain a signature of the X particle on primordial abundances of those elements. Possible signatures left on light element abundances expected in four different models are summarized.