New indirect searches of dark matter with the GAPS experiment

Novel Indirect Dark Mater Searches with the GAPS Experiment Luigi Volpicelli1 on behalf of the GAPS Collaboration 1 INFN - Sezione di Roma "Tor Vergata", V. della Ricerca Scientifica 1, I-00133 Rome, Italy Indirect dark mater (DM) experiments search for beyond standard model physics by focusing on daughter particles generated from potential DM-DM interaction or DM particle annihilation. The GAPS (General Antiparticle Spectrometer) experiment is designed to carry out indirect DM studies by searching for low-energy cosmic-ray antinuclei, antiprotons, and, especially, antideuterons and antihelium nuclei. The antideuteron flux, resulting from a purely secondary interaction of primary cosmic rays with the interstellar medium, is very low. Plausible beyond standard model theories predict DM candidates that could significantly enhance (about two orders of magnitude) the flux of this antideuteron population in space, especially in the low-energy (< 250 MeV/n) range; for this reason, antideuteron search in GAPS is almost background-free. Moreover, GAPS is designed to obtain unprecedented precision in low-energy antiproton measurements and possible anti-helium-3 detection. The detector itself revolves around a series of 10 Si(Li) planes – forming the tracker - surrounded by a plastic scintillator Time-of-Flight (ToF) system. This design has been optimized to achieve a novel antiparticle identification technique based on antinucleus capture and the subsequent exotic atom formation and decay through a series of atomic transitions emitting characteristic X-rays. Finally, the annihilation of the antinucleus with the atomic nucleus produces a nuclear star of several secondary particles, mainly pions, and protons, originating from a common vertex. The experiment is foreseen to be launched in late 2025, with the first long-duration balloon flight from Antarctica