The General Antiparticle Spectrometer (GAPS) - Hunt for dark matter using low-energy antideuterons

TL;DR

The GAPS experiment aims to detect low-energy cosmic-ray antideuterons as a novel method to search for dark matter, utilizing a unique detection technique during balloon flights in Antarctica.

Contribution

This paper introduces the GAPS detection approach and experimental setup for the first time, focusing on low-energy antideuteron detection for dark matter searches.

Findings

Design of a novel detection method for low-energy antideuterons.

Prototype flight scheduled to test detector performance at high altitude.

Potential for background-free detection of dark matter signatures.

Abstract

The GAPS experiment is foreseen to carry out a dark matter search using a novel detection approach to detect low-energy cosmic-ray antideuterons. The theoretically predicted antideuteron flux resulting from secondary interactions of primary cosmic rays with the interstellar medium is very low. So far not a single cosmic antideuteron has been detected by any experiment, but well-motivated theories beyond the standard model of particle physics, e.g., supersymmetry or universal extra dimensions, contain viable dark matter candidates, which could led to a significant enhancement of the antideuteron flux due to self-annihilation of the dark matter particles.This flux contribution is believed to be especially large at small energies, which leads to a high discovery potential for GAPS. GAPS is designed to achieve its goals via a series of ultra-long duration balloon flights at high altitude in Antarctica, starting in 2014. The detector itself will consist of 13 planes of Si(Li) solid state detectors and a time of flight system. The low-energy antideuterons (< 0.3 GeV/n) will be slowed down in the Si(Li) material, replace a shell electron, and form an excited exotic atom. The atom will be deexcited by characteristic x-ray transitions and will end its life by forming an annihilation pion star. This unique event structure will allow for nearly background free detection. To prove the performance of the different detector components at stratospheric altitudes, a prototype flight will be conducted in 2011 from Taiki, Japan.