Mengjiao Xiao (MIT)

Date: Tue. January 31st, 2023, 11:30 am-12:30 pm
Location: Foldy Room, Rockefeller 221

In Search of Cosmic-Ray Antinuclei from Dark Matter with the GAPS Experiment

The origin of dark matter is a driving question of modern physics. Finding dark
matter in the laboratory and elucidating its properties could revolutionize our
understanding of the fundamental building blocks of the universe. The common
challenges for dark matter searches in astrophysical signatures are large and
uncertain backgrounds. The General Antiparticle Spectrometer (GAPS) is a
balloon-borne experiment designed to identify low-energy cosmic antinuclei, in
particular antideuterons from dark matter annihilation or decay. With a novel
detection approach that uses the uniquely characterized atomic X-rays and
charged particles from the decay of exotic atoms, GAPS is sensitive to
antideuterons and even antihelium with the kinetic energy ≤0.25 GeV/n, which
offers an essentially background-free region to probe many generic dark matter
models. Additionally, GAPS will collect a high-statistics antiproton spectrum in an
unexplored energy range.

The GAPS instrument consists of a tracker of >1000 custom Si(Li) detectors; a
precision-timing, large-acceptance Time-of-Flight system; and a novel oscillating
heat pipe thermal system. GAPS is currently under integration and preparing for
the first Antarctic balloon flight in late 2023, while two follow-up flights are
planned. This talk will present the science impact of the GAPS experiment; its
custom-developed instrument technology, including the design principle,
commissioning of the GAPS functional prototype, and integration of GAPS full
payload, with special focus on the construction of the Si(Li) tracker; and the path
towards the initial flight.