The General AntiParticle Spectrometer (GAPS) is a long-duration ballon-borne experiment, designed to detect low-energy cosmic-ray antinuclei (below similar to 0.25 GeV/n) as potential indirect signal of Dark Matter. Unlike traditional detection methods -relying for example on magnetic spectrometers-GAPS employs a novel approach based on the formation, de-excitation, and decay of exotic atoms, enabling the identification of antinuclei without the use of a magnet. The mission will investigate the low-energy sector of the cosmic-ray spectrum that has remained largely unexplored, allowing for a critical test of theoretical models predicting the flux of low-energy antideuterons; in addition, GAPS is expected to achieve unprecedented sensitivity to cosmic antiprotons and to provide leading sensitivity to the low-energy antihelium nuclei in the cosmic radiation. During its pre-flight campaign in Antarctica (November/December 2024), the apparatus was able to perform several muon runs for both scientific and calibration purposes. Performance studies related to the detection of this particle population at sea level are currently being conducted before the scheduled launch during the 2025/26 season.
Aoyama4 et al. (Wed,) studied this question.