The GAPS experiment: Low-energy antinuclei measurements for dark matter searches

GAPS (General Anti-Particle Spectrometer) is a balloon-borne experiment designed to measure low-energy (<0.25 GeV/n) cosmic antinuclei (i.e., antiprotons, antideuterons, and antihelium nuclei) as signature of dark matter annihilation or decay. According viable beyond-the-Standard Model theories, the predicted signal in antideuterons nuclei channels several orders magnitude higher than astrophysical background. The will conduct series at least three long-duration balloon flights high altitudes from Antarctica. instrument composed Si(Li) tracker surrounded by Time-of-Flight system made plastic scintillators. uses novel exotic-atom detection technique which an antinucleus captured material forms exotic atom. This excited atom decays within order nanoseconds emitting X-rays specific energies defined atomic transitions annihilates secondary particles (mainly pions protons). measured quantities (e.g., dE/dx, time flight, vertex position, energies, etc.) allow for identifying with precision.