Recent Media and News Stories

Kyle Leach, professor of physics at Colorado School of Mines, has been elected a Fellow of the American Physical Society (APS). APS, the world’s second-largest organization of physicists, limits the number of newly elected Fellows each year to no more than one-half percent of its current non-student membership. Leach was recommended for the honor by his peers in the APS Division of Nuclear Physics. Leach was recognized “for pioneering work in applying superconducting sensors to the study of neutrino properties.”

Precise measurement of beryllium-7 nuclear decay recoils directly probes the quantum properties of the neutrino for the first time.

The nuclear electron capture decay of highly localized beryllium-7 atoms inside a superconducting tunnel junction sensor provides direct access to quantum properties of the neutrino via a precision measurement of the recoiling lithium-7 atom.

A member of the Mines faculty since 2015, Leach has raised over $4.5 million in research funding as a lead principal investigator at Mines, including the U.S. Department of Energy Early Career Award, Gordon and Betty Moore Foundation Experimental Physics Investigator Award, and Francis M. Pipkin Award from the American Physical Society. He is the head of the Electroweak Interactions Group at Mines and spokesperson for the Beryllium Electron capture in Superconducting Tunnel junctions (BeEST) Experiment.

Pitching neutrinos can be easier than catching them. Because the lightweight particles stream mostly unencumbered through any matter they encounter, neutrino detectors must monitor gargantuan volumes of water or other material, ever vigilant for the signs of a rare neutrino interaction, wherever it may occur. On the other hand, the processes that create neutrinos, including certain nuclear decays and particle reactions, can be readily localized and precisely studied even in a tabletop experiment.

Kyle Leach, associate professor of physics, was honored with the 2025 Francis M. Pipkin Award by the American Physical Society (APS). Leach was awarded “for initiating and establishing new measurement techniques using rare-isotope-doped superconducting sensors as sensitive probes of fundamental physics in the electroweak sector.”

The first direct measurement of the size of the neutrino, a fundamental particle, suggests they are at least larger than an atomic nucleus – but they could potentially be trillions of times larger.

Part of the problem in answering this question is that, rather than being spherical, quantum mechanics tells us that particles are inherently fuzzy waves, moving and vibrating as they travel through space. Physicists mark the boundaries of a particle, and thus its size, by looking for its wave packet, an area inside which the wave vibrates strongly, and beyond which it sharply trails off.

Neutrinos are thought to be the second most common particles in the universe after photons, and the most plentiful ones with mass, but it’s not that long ago that physicists wondered if we would ever be able to prove their existence experimentally. They interact so weekly with other forms of matter, including our detectors, that only the tiniest subfraction can be observed. The recent (indirect) detection of one 35 times more energetic than the previous record holder shows how enormous the gaps are in what we have seen of them. 

The BeEST experiment has set new lower limits on the size of the neutrino’s wave packet. How big is a neutrino? Though the answer depends on the physical process that created it, knowledge of the size of neutrino wave packets is at present so wildly unconstrained that every measurement counts. New results from the Beryllium Electron capture in Superconducting Tunnel junctions (BeEST) experiment set new lower limits on the size of the neutrino’s wave packet in terrestrial experiments – though theorists are at odds over how to interpret the data.

Quantum particles travel as waves, with ripples that are related to the probability of finding a particle at a given location. A wave packet is the set of ripples corresponding to a single particle. The new experiment sets a limit on the size of the wave packet for neutrinos produced in a particular type of radioactive decay, Leach’s team reports in a paper submitted April 3 to arXiv.org. The particles have a wave packet size of at least 6.2 trillionths of a meter.

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.”

Researchers at Yale, Berkeley, FRIB, and Mines have proposed a new method to search for invisible particles called sterile neutrinos using a glass nanoparticle suspended by laser light.

A Colorado School of Mines professor is among the inaugural cohort of experimental physicists to receive a grant from the Gordon and Betty Moore Foundation.

Kyle Leach, associate professor of physics, was awarded $1.25 million over the next five years to support his fundamental investigation of the subatomic world using radioactive isotopes implanted in superconducting quantum sensors. He is presently on research sabbatical at the Facility for Rare Isotope Beams at Michigan State University until summer 2023.

The Gordon and Betty Moore Foundation has awarded grants to support sixteen U.S. experimental physicists. Each investigator will receive $1,250,000 over the next five years to advance the scientific frontier in experimental physics. These awards provide an opportunity for outstanding scientists to pursue transformative research during a critical time in their careers directly following attainment of tenure. This funding allows physicists, during some of their most creative years, to concentrate on their research and build collaborative relationships that enable innovative discoveries.

An international team has performed one of the world’s most sensitive laboratory searches for a subatomic particle called the “sterile neutrino.” These hypothetical particles may explain dark matter. They may also explain why the Universe contains more matter than antimatter. The novel experiment uses radioactive beryllium-7 atoms created at the TRIUMF facility in Canada. The research team then implants these atoms into sensitive superconductors cooled to near absolute-zero.

As part of the Beryllium Electron capture in Superconducting Tunnel junctions Experiment (BeEST), an international team that includes researchers from TRIUMF has published new measurements for the exclusion limits for sterile neutrinos. The findings, which improve upon previous work by an order of magnitude, were published last week in Physical Review Letters.

A team of interdisciplinary researchers, led by Lawrence Livermore National Laboratory (LLNL) and the Colorado School of Mines, has demonstrated the power of using nuclear decay in high-rate quantum sensors in the search for sterile neutrinos. The findings are the first measurements of their kind.

So-called “sterile neutrinos” are theoretically predicted new particles that offer what could be the brightest possibility in the quest for understanding the dark matter in our universe. Unlike the known “active” neutrinos in the Standard Model of particle physics, these sterile neutrinos do not interact with normal matter as they move through space, thus making them very difficult to detect.

Experiments have spotted anomalies hinting at a new type of neutrino, one that would go beyond the standard model of particle physics and perhaps open a portal to the dark sector. But no one has ever directly observed this hypothetical particle. Now a quantum dark matter detector and a proposed particle accelerator dreamt up by machine learning are poised to prove whether the sterile neutrino exists.

Past TRIUMF post-doctoral researcher and current TRIUMF user Dr. Kyle Leach has been awarded the United States Department of Energy’s (US DOE) prestigious Early Career Research Award for his work developing superconducting quantum sensors for hunting sterile neutrinos. Leach’s group, the Electroweak Interactions Group at the Colorado School of Mines, will be pursuing the work at TRIUMF as part of the Beryllium Electron-capture with Superconducting Tunnel junctions (colloquially ‘the BeEST’ (“beast”)) experiment.

Kyle Leach, assistant professor of physics at Colorado School of Mines, has been awarded the U.S. Department of Energy’s prestigious Early Career Research Award to employ superconducting quantum sensors in the search for sterile neutrinos.

The Department of Energy (DOE) announced the selection of 76 scientists from across the nation to receive funding for research as part of the DOE Office of Science’s Early Career Research Program. The program, now in its thirteenth year, is designed to bolster the nation’s scientific workforce by providing support to exceptional researchers during crucial early career years, when many scientists do their most formative work.

This year, two visiting awards were given: Michelle Kuchera from Davidson College in North Carolina and Kyle Leach from the Colorado School of Mines.

Kuchera is a computational physicist with research interests in machine learning, nuclear physics, and algorithm development for data analysis. She focuses on applying these methods to improve analyses of large datasets in nuclear physics experiments. Leach performs nuclear structure studies relevant to tests of the Standard Model.