In a recent Physical Review X Quantum paper, a team of scientists from Lawrence Berkeley National Laboratory, the Colorado School of Mines, Yale University, and FRIB explains its new method to search for invisible particles called sterile neutrinos using optically levitating nanospheres. The American Physical Society featured the paper as a “Physics Viewpoint.”

Neutrinos are elusive particles that require large detectors to identify their interactions. However, if nuclei that decay by emitting neutrinos are implanted in tiny nanoparticles, then the momentum of the neutrino emitted in the decay can be measured. This is not accomplished by detecting the neutrino itself, but by measuring the recoil of the entire particle from which it escapes. Precise nanoparticle recoil measurements may then allow the neutrino properties to be inferred, including its mass.

New techniques allow the measurement of a levitated nanoparticle’s momentum in the quantum regime. These techniques are sensitive enough to measure the momentum of a single neutrino emitted from such a nanoparticle. If an anomalous momentum was measured for even a tiny fraction of such decays, it could indicate the existence of a previously undetected heavy type of neutrino.

Extending the same ideas to large arrays of nanoparticles could probe many orders of magnitude beyond the reach of existing searches for heavy neutrinos. Future extensions of these ideas may allow even the masses of the lighter neutrinos to be determined with similar techniques.  For all of the presented studies in this paper, the rare isotopes required will be produced at FRIB and loaded into the nanospheres. 

The authors of the paper include Kyle Leach, associate professor of physics at the Colorado School of Mines and visiting professor at FRIB.

Read the American Physical Society release here.

This material is based upon work supported by the U.S. Department of Energy; the U.S. National Science Foundation; the U.S. Navy Office of Naval Research; the Gordon and Betty Moore Foundation; and the Heising-Simons Foundation.

Michigan State University (MSU) operates the Facility for Rare Isotope Beams (FRIB) as a user facility for the U.S. Department of Energy Office of Science (DOE-SC), supporting the mission of the DOE-SC Office of Nuclear Physics. User facility operation is supported by the DOE-SC Office of Nuclear Physics as one of 28 DOE-SC user facilities.

The U.S. Department of Energy Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of today’s most pressing challenges. For more information, visit energy.gov/science.