Particle and Astroparticle Physics Seminar

Antinucleons in Cosmic Rays? Using GAPS to Open a New Window in the Search for Dark Matter

Ralph Bird

UCLA

Dark matter remains one of the biggest mysteries in physics, though recent years have seen significant progress in constraining its properties, its nature and origin remain unknown. In the plethora of dark matter models, WIMPS (weakly interacting massive particles) are one of the best motivated and have been the subject of many direct, indirect and collider searches. Cosmic rays provide one of the key avenues to search for the products of WIMP annihilation or decay, yet they face many challenges associated, in particular, with irreducible astrophysical backgrounds. Cosmic ray antinucleons provide a new channel to search for these products, which, at low energies, is almost background free. GAPS, the General Antiparticle Spectrometer, is designed to search for low energy (100-300 MeV/nucleon) antinucleons (antiprotons, antideuterons and antihelium) using a novel exotic atom technique. By detecting the atomic X-rays and charged particles produced in the decay of exotic atom it will provide an almost background free antinucleon detection capability, which is critical to search for these rare events. Funded to fly from McMurdo station in the austral summer of 2020, I will present the GAPS experiment, the science that motivates it, how it relates to other antinucleon searches and the status of the current work.