{"id":1112863,"date":"2026-07-26T19:41:19","date_gmt":"2026-07-26T19:41:19","guid":{"rendered":"https:\/\/www.europesays.com\/uk\/1112863\/"},"modified":"2026-07-26T19:41:19","modified_gmt":"2026-07-26T19:41:19","slug":"scientists-solve-a-decades-old-mystery-inside-atomic-nuclei","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/uk\/1112863\/","title":{"rendered":"Scientists Solve a Decades-Old Mystery Inside Atomic Nuclei"},"content":{"rendered":"

\"Giant<\/a>A long-standing puzzle in nuclear physics may finally have an answer: unexpected low-energy gamma rays in zinc-70 appear to come from magnetic transitions hidden within the nucleus. Credit: SciTechDaily.com<\/p>\n

Results from an experiment at the Facility for Rare Isotope Beams answer a fundamental question about the structure of atomic nuclei and help explain how different elements formed in space.<\/strong><\/p>\n

For decades, some atomic nuclei have emitted more low-energy gamma rays than theory could explain. A collaboration led by researchers at the Facility for Rare Isotope Beams (FRIB) has now traced this mysterious excess in zinc-70 to magnetic transitions occurring inside the nucleus.<\/p>\n

The findings are reported in a study recently published in Nature. By resolving a long-standing problem in nuclear physics, the result could improve calculations used to understand nuclear structure and the formation of elements in space.<\/p>\n

The international collaboration brought together scientists from 25 institutions across the United States, Canada, Italy, Germany, Norway and South Korea.<\/p>\n

Magnetic transitions explain the excess<\/p>\n

Gamma rays belong to the same broad family of electromagnetic radiation as visible light and radio waves. Excited atomic nuclei release gamma rays as they move into lower and more stable energy states. Physicists describe how often nuclei emit gamma rays at different energies through a measurement called the gamma-ray strength function.<\/p>\n

Electromagnetic transitions between nuclear states can be either electric or magnetic, depending on how protons and neutrons rearrange inside the nucleus as energy is released. For decades, experiments have revealed an unexpected rise in low-energy gamma rays from certain nuclei. This feature, known as the low-energy enhancement (LEE), appears in the gamma-ray strength function, but its physical origin had remained uncertain.<\/p>\n

Scientists from four national laboratories contributed, including the NNSA laboratories Lawrence Livermore and Los Alamos.<\/p>\n

The project reflects FRIB\u2019s broader partnerships with national laboratories, which connect fundamental nuclear research with national security applications while providing practical training for future members of the nuclear workforce.<\/p>\n

\u201cThis low-energy enhancement wasn\u2019t predicted by theory, so it was kind of a shock to the community when it was first observed,\u201d said Eleanor Ronning, lead author of the study and former FRIB graduate student who is now a postdoctoral research fellow at the National Institute for Nuclear Physics in Padova, Italy. \u201cIt is difficult to predict where LEE occurs \u2014 we don\u2019t know which nuclei will exhibit it.\u201d<\/p>\n

The new measurements provide strong evidence that magnetic transitions produce the enhancement.<\/p>\n

\u201cThis is a key step forward,\u201d said Andrea Richard, co-lead of the study and assistant professor and interim director of the Edwards Accelerator Laboratory at Ohio University. \u201cWe now have a consistent explanation that connects experimental observations with theory.\u201d<\/p>\n

The finding changes element formation models<\/p>\n

Resolving the origin of LEE matters beyond the internal structure of atomic nuclei. The effect also influences the nuclear reactions that create elements in astrophysical environments.<\/p>\n

LEE increases the expected frequency of neutron-capture reactions, in which an atomic nucleus absorbs a neutron. These reactions contribute to the production of heavy elements during events such as supernova explosions and neutron star mergers.<\/p>\n

When the enhancement affects many nuclei, its combined influence can substantially alter calculated reaction rates. Those changes affect models of stellar nuclear processes, nuclear energy systems and applications connected with the NNSA\u2019s national security work.<\/p>\n

Measuring LEE is difficult because the signal is weak and can be obscured by background noise. Separating it requires highly sensitive instruments and carefully developed analytical methods.<\/p>\n

\u201cOur collaboration has been searching for ways to identify the nature of this low-energy enhancement in gamma-ray emission for over a decade,\u201d said Artemis Spyrou, professor of physics at FRIB and in Michigan State University\u2019s Department of Physics and Astronomy. \u201cThis result only became possible thanks to the development of new experimental capabilities and new analysis techniques that did not exist when we began.\u201d<\/p>\n

Sean Liddick, professor of chemistry at FRIB, interim chairperson of MSU\u2019s Department of Chemistry, and Ronning\u2019s graduate advisor, said the study depended on capabilities available only at FRIB.<\/p>\n

\u201cWe used a novel experimental technique that combines specialized instruments in a way that effectively used the entire facility,\u201d Liddick said. \u201cIt is exciting to see that effort lead to such a clear result.\u201d<\/p>\n

Two pathways isolate the hidden signal<\/p>\n

The researchers focused on low-energy gamma rays from zinc-70, a nucleus suspected of showing LEE and whose arrangement of known energy levels is already well documented. Rather than producing zinc-70 through only one route, they examined the beta decay of two different states of its parent nucleus, copper-70.<\/p>\n

One copper-70 beam contained nuclei in the ground state, while the other contained nuclei in an excited state known as an isomer. These two starting points created separate pathways into zinc-70, filling different combinations of its energy levels and offering complementary views of the nucleus.<\/p>\n

Producing highly pure beams of both copper-70 states required FRIB\u2019s Low Energy Beam and Ion Trap (LEBIT), a high-precision mass spectrometer capable of separating nuclei with extremely small differences in mass and energy.<\/p>\n

\u201cWe used LEBIT in this way for the first time,\u201d said Ryan Ringle, associate professor of physics at FRIB and LEBIT group leader. \u201cIt was an interesting challenge to work on, which provided additional training opportunities for our group\u2019s graduate students. This new technique for isomer separation opens the door to study many more nuclei and motivates technical developments to expand our capabilities in this area.\u201d<\/p>\n

After the copper-70 nuclei decayed, the Summing NaI (SuN) detector<\/a> recorded the gamma rays released by zinc-70. The researchers then used two analytical approaches, the beta-Oslo method and the Shape method, to calculate the gamma-ray strength function produced through each starting state.<\/p>\n

Comparing the two strength functions allowed the researchers to determine conclusively that magnetic transitions inside zinc-70 generate the low-energy enhancement. The result gives nuclear theory a new experimental benchmark and provides guidance for future studies.<\/p>\n

\u201cWe look forward to applying this separated-isomers technique to more nuclei,\u201d Liddick said. \u201cKnowing which nuclei should exhibit this low-energy enhancement is key to designing experiments to investigate them at facilities like FRIB and to improve models of how elements are created in astrophysical environments.\u201d<\/p>\n

Collaboration builds future research capacity<\/p>\n

The project also demonstrates how collaborations involving numerous institutions, graduate students and postdoctoral researchers can sustain complex experiments over many years.<\/p>\n

Ronning and Richard helped write the experimental proposal for FRIB\u2019s second call for submissions through its Program Advisory Committee. Both were early-career researchers at the time. Ronning was a graduate student at FRIB, while Richard was a postdoctoral scholar at LLNL.<\/p>\n

After completing her first postdoctoral position at MSU, where she worked on nuclear astrophysics and national security, Richard sought to connect fundamental research more closely with the NNSA\u2019s mission. That goal led her to a postdoctoral position at LLNL. She now continues working across basic science and national security from Ohio University.<\/p>\n

\u201cThe combined expertise of our research teams is what really made it all possible,\u201d Richard said. \u201cIt was a privilege to work with the various teams across institutions over the years. It was a formative experience as an early-career researcher.\u201d<\/p>\n

For Ronning, publication marked the completion of a project she had followed from its earliest planning stages.<\/p>\n

\u201cWorking on the entire process \u2014 from writing the proposal and running the experiment to publishing the paper in Nature \u2014 has been a rewarding experience,\u201d Ronning said.<\/p>\n

Reference: \u201cMagnetic character of the low-energy enhancement in 70Zn\u201d by E. K. Ronning, A. L. Richard, S. N. Liddick, A. Spyrou, R. Ringle, H. Arora, H. C. Berg, J. M. Berkman, D. L. Bleuel, K. Bosmpotinis, S. E. Campbell, X. Chen, B. P. Crider, R. J. Coleman, P. A. DeYoung, A. A. Doetsch, H. Erington, T. Gaballah, N. D. Gamage, E. C. Good, B. Greaves, A. C. Hartley, J. Huffman, C. M. Ireland, C. Izzo, R. Jain, A. C. Larsen, J. E. L. Larsson, R. S. Lubna, F. M. Maier, M. J. Mogannam, D. M\u00fccher, M. R. Mumpower, G. Owens-Fryar, T. H. Ogunbeku, D. P. Scriven, M. K. Smith, C. S. Sumithrarachchi, A. Sweet, K. Taft, A. Tsantiri, S. Uthayakumaar and M. Wiedeking, 15 July 2026, Nature.
DOI: 10.1038\/s41586-026-10758-3<\/a><\/p>\n

This research is based upon work supported by the U.S. Department of Energy Office, the U.S. National Science Foundation, the National Nuclear Security Administration, the U.S. Nuclear Data Program, the Research Council of Norway, the Norwegian Nuclear Research Center, the Natural Sciences and Engineering Research Council of Canada and the Canada Foundation for Innovation.<\/p>\n

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Follow us on Google<\/a> and Google News<\/a>.<\/b><\/p>\n","protected":false},"excerpt":{"rendered":"A long-standing puzzle in nuclear physics may finally have an answer: unexpected low-energy gamma rays in zinc-70 appear…\n","protected":false},"author":2,"featured_media":1112864,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_share_on_mastodon":"0"},"categories":[3845],"tags":[143249,11029,43255,45440,51277,74,70,16,15],"class_list":["post-1112863","post","type-post","status-publish","format-standard","has-post-thumbnail","category-physics","tag-gamma-ray","tag-magnetism","tag-michigan-state-university","tag-neutron-star","tag-nuclear-physics","tag-physics","tag-science","tag-uk","tag-united-kingdom"],"share_on_mastodon":{"url":"","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/1112863","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/comments?post=1112863"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/1112863\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media\/1112864"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media?parent=1112863"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/categories?post=1112863"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/tags?post=1112863"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}