Rapidity dependence of nuclear coalescence: impact on cosmic ray antinuclei

Abstract

Upcoming studies at the Large Hadron Collider (LHC) aim to extend the rapidity coverage in measurements of the production cross section of antinuclei $\bar{\mathrm{d}}$ and $\overline{{}^3\mathrm{He}}$. We illustrate the impact of such studies on cosmic ray (CR) flux predictions, important, in turn, for the interpretation of results from CR experiments. We show that, in terms of the rapidity effect, covering the range $|y|<1.5$ at the LHC should be sufficient for the astrophysical CR calculation. Important extrapolation remains in other aspects of the problem, notably $\sqrt{s}$.

Comments: 8 pages, 5 figures. v2: updated references, including updated measurements of anti-He3 yield with reduced uncertainty. Added plots for anti-protons and anti-He3 in appendix