Collaborative Research: Axion Resonant InterAction DetectioN Experiment (ARIADNE)

Northwestern University, Evanston IL

Investigators

Abstract

Multiple astronomical observations have established that about 85% of the matter in the universe is not made of known particles. Deciphering the nature of this so-called Dark Matter is of fundamental importance to cosmology, astrophysics, and high-energy particle physics. One of the most exciting quests in particle physics is the search for new particles beyond the Standard Model of particle physics. Extensions of the Standard Model predict not only new particles with large masses but also some with very small masses. Such a candidate is the axion, which has been introduced to explain the smallness of Charge-Parity (CP) violation in Quantum Chromodynamics and which turns out to also be a prime candidate for a constituent of the dark matter in the universe. This award will provide funds for R&D towards developing a new experiment to search for axion-like interactions between nuclei at sub-millimeter ranges. While participating in this research, a team of postdocs, graduate students and undergraduate researchers will be broadly trained in the various techniques of experimental atomic physics such as low-temperature physics, magnetic shielding, vacuum systems and modeling. The experiment involves a rotating non-magnetic mass to source the axion field, and a dense ensemble of laser-polarized He-3 nuclei to detect the axion field by NMR. The signal from an axion field can be resonantly enhanced by properly modulating the axion potential at the nuclear spin precession frequency. The method has the potential to improve previous experimental and astrophysical bounds on axions by several orders of magnitude and probe deep into the theoretically interesting regime for the Peccei-Quinn (PQ) axion. The experiment is also sensitive to more exotic axion-like particles. It is estimated that this method can ultimately exceed present laboratory constraints on spin-dependent short-range forces by up to eight orders of magnitude and can improve on the combined laboratory/astrophysical limits by a factor of 10^4 in the prime axion range of f_a between 10^9 and 10^12, probing deep into the theoretically interesting regime for the PQ axion. In contrast to cosmic axion searches, the setup is sensitive to the axion even if it does not make up most of the dark matter. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.