Deuteron and Antideuteron Production Simulation in Cosmic-ray Interactions

TL;DR

This paper simulates deuteron and antideuteron production in cosmic-ray interactions across a wide energy range, revealing that antideuteron production is lower at low energies than previously thought, impacting astrophysical flux predictions.

Contribution

It introduces the first evaluation of the coalescence parameter $p_0$ for deuterons over a broad energy spectrum and shows that $p_0$ for antideuterons varies with energy, challenging prior assumptions.

Findings

$p_0$ for deuterons determined across energies for the first time.

Antideuteron production cross section is at least 20 times lower at low energies.

Antideuteron $p_0$ is not constant, contrary to previous models.

Abstract

The study of the cosmic-ray deuteron and antideuteron flux receives an increasing interest in current astrophysics investigations. For both cases an important contribution is expected from the nuclear interactions of primary cosmic rays with intergalactic matter. In this work, deuteron and antideuteron production from 20 to 2.6$\times$10$^{7}$ GeV beam energy in p+p and p+A collisions were simulated using EPOS-LHC and Geant4's FTFP-BERT Monte Carlo models by adding an event-by-event coalescence model afterburner. These estimates depend on a single parameter ($p_0$) obtained from a fit to the data. The $p_0$ for deuterons in this wide energy range was evaluated for the first time. It was found that $p_0$ for antideuterons is not a constant at all energies as previous works suggested and as a consequence the antideuteron production cross section can be at least 20 times smaller in the low collision energy region, than earlier estimations.