Cosmic rays, anti-helium, and an old navy spotlight

Understand

Cosmic-ray anti-deuterium and anti-helium have long been suggested as probes of dark matter, as their secondary astrophysical production was thought extremely scarce.

• But how does one actually predict the secondary flux? Anti-nuclei are dominantly produced in pp collisions, where laboratory cross section data is lacking.
• We make a new attempt at tackling this problem by appealing to a scaling law of nuclear coalescence with the physical volume of the hadronic emission region.
• The same volume is probed by Hanbury Brown-Twiss (HBT) two-particle correlations.