MIT grad student Chiara Salemi and Professor Lindley Winslow use the ABRACADABRA instrument to reveal insights into dark matter.

On the first floor of MIT’s Laboratory for Nuclear Science hangs an instrument called “A Broadband/Resonant Approach to Cosmic Axion Detection with an Amplifying B-field Ring Apparatus,” or ABRACADABRA for short. As the name states, ABRACADABRA’s goal is to detect axions, a hypothetical particle that may be the primary constituent of dark matter, the unseen and as-of-yet unexplained material that makes up the bulk of the universe.

Extremely light and weakly interacting particles may play a crucial role in cosmology and in the ongoing search for dark matter. Unfortunately, however, these particles have so far proved very difficult to detect using existing high-energy colliders. Researchers worldwide have thus been trying to develop alternative technologies and methods that could enable the detection of these particles.

Over the past few years, collaborations between particle and atomic physicists working at different institutes worldwide have led to the development of a new technique that could be used to detect interactions between very light bosons and neutrons or electrons. Light bosons, in fact, should change the energy levels of electrons in atoms and ions, a change that could be detectable using the technique proposed by these teams of researchers.

Using this method, two different research groups (one at Aarhus University in Denmark and the other at Massachusetts Institute of Technology) recently performed experiments aimed at gathering hints of the existence of dark bosons, elusive particles that are among the most promising dark matter candidates or mediators to a dark sector. Their findings, published in Physical Review Letters, could have important implications for future dark matter experiments.

You can’t see it. You can’t feel it. But the substance scientists refer to as dark matter could account for five times as much “stuff” in the universe as the regular matter that forms everything from trees, trains and the air you breathe, to stars, planets and interstellar dust clouds.

Though scientists see the signature of dark matter indirectly in the way large objects orbit one another—particularly how stars swirl around the centers of spiral galaxies—no one knows yet what comprises this substance. One of the candidates is a Z’ boson, a fundamental particle that has been theorized to exist but never detected.

A new proposed experiment could help scientists determine whether Z’ bosons are real, in that way identifying a possible candidate for dark matter. To accomplish this task, researchers from the National Institute of Standards and Technology (NIST), the University of Groningen in the Netherlands, the Canadian particle accelerator center TRIUMF and other collaborators are working to make the most accurate measurements to date of a nuclear property that is extremely difficult to measure, called nuclear spin-dependent parity violation (NSD-PV).