[Paper Review] Primordial nucleosynthesis constraint on massive, stable, strongly interacting particles

R. N. Mohapatra, Vigdor L. Teplitz|arXiv (Cornell University)|Apr 27, 1998

Dark Matter and Cosmic Phenomena4 citations

TL;DR

This paper constrains the primordial abundance of massive, stable, strongly interacting particles (X) using nucleosynthesis data, finding limits on the X-to-baryon ratio η_X between 3×10⁻¹¹ and 3×10⁻¹⁶ for X masses up to 10 TeV. The bounds, derived from anomalous nucleus searches, challenge the existence of such particles unless their interaction with nucleons is significantly weaker than the Λ-N force.

ABSTRACT

Heavy, stable, strongly interacting massive particles (X), have recently been discussed by many authors in theoretical and phenomenological contexts. We address the question of constraints on these particles from searches for anomalous nuclei containing them that would be formed during primordial nucleosynthesis. Based on existing data and previous investigations of primordial nucleosynthesis of anomalous nuclei, we find a limit on the abundance ratio $\\eta_X\\equiv n_X/n_B$ in the range of $3\ imes 10^{-11}$ to $3\ imes 10^{-16}$ for masses up to 10 TeV with a possible curious window between 93 to 100 GeV for which there seems to be an absence of data. These bounds are orders of magnitude below the expectations for this abundance based on the standard big bang model and generic properties of strongly interacting particles, but depend on the $X-N$ interaction being sufficiently strong. Our bounds raise serious questions about the existence of such particles in nature. Since we draw heavily on our intuition from information on nuclear forces in the $\\Lambda-N$ system, we estimate how much weaker than the $\\Lambda-N$ potential the $X-N$ potential must be in order to evade these bounds.

Motivation & Objective

• To assess the cosmological viability of massive, stable, strongly interacting particles (X) via primordial nucleosynthesis constraints.
• To identify bounds on the X-baryon abundance ratio η_X = n_X/n_B from observed anomalies in light nuclei.
• To evaluate whether such particles could exist in nature given the derived limits and their interaction strength with nucleons.
• To estimate the required weakening of the X-N interaction relative to the Λ-N potential to evade nucleosynthesis constraints.

Proposed method

• Analysis of existing data on primordial nucleosynthesis to detect anomalous nuclei containing X particles.
• Use of theoretical models of X-N interactions to simulate formation of exotic nuclei during Big Bang nucleosynthesis.
• Comparison of predicted abundances of X-containing nuclei with observational limits to derive upper bounds on η_X.
• Application of intuition from the Λ-N system to estimate the required suppression of X-N interaction strength.
• Numerical estimation of the minimum required reduction in X-N potential strength to avoid detection constraints.
• Identification of a potential data gap between 93–100 GeV where constraints are absent.

Experimental results

Research questions

• RQ1 What upper limits can be placed on the primordial abundance ratio η_X = n_X/n_B for massive, stable, strongly interacting particles?
• RQ2 How do constraints from anomalous nuclei formed during primordial nucleosynthesis affect the viability of X particles?
• RQ3 What strength must the X-N interaction have to evade nucleosynthesis bounds, relative to the Λ-N force?
• RQ4 Why is there a possible absence of constraints in the 93–100 GeV mass window for X particles?
• RQ5 To what extent must the X-N potential be weaker than the Λ-N potential to remain consistent with current data?

Key findings

• The paper establishes a constraint on the X-to-baryon abundance ratio η_X in the range of 3×10⁻¹¹ to 3×10⁻¹⁶ for X masses up to 10 TeV.
• Constraints are strongest for X masses below 93 GeV and above 100 GeV, with a notable gap in the 93–100 GeV range where no data exist.
• The derived bounds are orders of magnitude smaller than expected in the standard big bang model for strongly interacting particles.
• The existence of such X particles is called into question unless their interaction with nucleons is significantly weaker than the Λ-N force.
• The X-N potential must be substantially weaker than the Λ-N potential to evade nucleosynthesis constraints, though the exact threshold depends on X mass and interaction dynamics.
• The absence of constraints in the 93–100 GeV window suggests a possible loophole, but also a critical data gap in current observational coverage.