{"id":170263,"date":"2025-08-23T23:03:11","date_gmt":"2025-08-23T23:03:11","guid":{"rendered":"https:\/\/www.europesays.com\/us\/170263\/"},"modified":"2025-08-23T23:03:11","modified_gmt":"2025-08-23T23:03:11","slug":"record-breaking-watermelon-nucleus-could-rewrite-atomic-science","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/us\/170263\/","title":{"rendered":"Record-Breaking \u201cWatermelon\u201d Nucleus Could Rewrite Atomic Science"},"content":{"rendered":"

\t\t\"Henna<\/a>The study is part of Henna Kokkonen\u2019s doctoral thesis. Credit: Tommi Sassi<\/p>\n

After more than 30 years, physicists in Finland have uncovered the heaviest nucleus ever seen to emit a proton, a rare process that sheds light on the limits of atomic matter.<\/strong><\/p>\n

The discovery of 188-astatine \u2014 an oddly \u201cwatermelon-shaped\u201d nucleus \u2014 not only sets a new record but also hints at nuclear interactions never before observed.<\/p>\n

Historic Breakthrough in Proton Emission Research<\/p>\n

Radioactive decay has long been central to nuclear physics, serving as a key to understanding how atomic nuclei behave. At the University of Jyv\u00e4skyl\u00e4 in Finland, researchers have now measured the heaviest nucleus ever observed to undergo proton emission.<\/p>\n

\u201cProton emission is a rare form of radioactive decay, in which the nucleus emits a proton to take a step towards stability,\u201d says Doctoral Researcher Henna Kokkonen from the University of Jyv\u00e4skyl\u00e4.<\/p>\n

Studying Exotic Nuclei Is Difficult, But Not Impossible<\/p>\n

The newly identified nucleus is the lightest isotope of astatine known so far, 188At, which contains 85 protons and 103 neutrons. Investigating nuclei like this is especially difficult because they exist for only a very short time and are produced in extremely small numbers, requiring highly precise experimental methods.<\/p>\n

\u201cThe nucleus was produced in a fusion-evaporation reaction by irradiating a natural silver target with an 84Sr ion beam,\u201d says Academy Research Fellow Kalle Auranen from the University of Jyv\u00e4skyl\u00e4. \u201cThe new isotope was identified using the detector setup of the RITU recoil separator.\u201d<\/p>\n

Study Reveals New Findings on Heavy Nuclei<\/p>\n

In addition to the experimental results, the study expanded a theoretical model to interpret the measured data. Through the model, the nucleus can be interpreted as strongly prolate, i.e. \u201cwatermelon shaped.\u201d<\/p>\n

\u201cThe properties of the nucleus suggests a trend change in the binding energy of the valence proton,\u201d says Kokkonen. \u201cThis is possibly explained by an interaction unprecedented in heavy nuclei.\u201d<\/p>\n

A Doctoral Journey Building on Past Discoveries<\/p>\n

The study is part of Kokkonen\u2019s doctoral thesis and a direct scientific follow-up to her master\u2019s thesis, in which she discovered a new type of atomic nucleus, the 190-astatatine. The thesis article was published in the Physical Review C journal in 2023.<\/p>\n

\u201cIsotope discoveries are rare worldwide, and this is the second time I have had the opportunity to be part of making history,\u201d Kokkonen rejoices. \u201cEvery experiment is challenging, and it feels great to do research that improves understanding of the limits of matter and the structure of atomic nuclei.\u201d<\/p>\n

The research article was written as part of an international research collaboration involving experts in theoretical nuclear physics. The study was published in the renowned Nature Communications on May 29, 2025.<\/p>\n

Reference: \u201cNew proton emitter 188At implies an interaction unprecedented in heavy nuclei\u201d by Henna Kokkonen, Kalle Auranen, Pooja Siwach, Paramasivan Arumugam, Andrew D. Briscoe, Sarah Eeckhaudt, Lidia S. Ferreira, Tuomas Grahn, Paul T. Greenlees, Pete Jones, Rauno Julin, Sakari Juutinen, Matti Leino, Ari-Pekka Lepp\u00e4nen, Enrico Maglione, Markus Nyman, Robert D. Page, Janne Pakarinen, Panu Rahkila, Jan Sar\u00e9n, Catherine Scholey, Juha Sorri, Juha Uusitalo and Martin Venhart, 29 May 2025, Nature Communications.
DOI: 10.1038\/s41467-025-60259-6<\/a><\/p>\n

Never miss a breakthrough: Join the SciTechDaily newsletter.<\/a><\/b><\/p>\n","protected":false},"excerpt":{"rendered":"The study is part of Henna Kokkonen\u2019s doctoral thesis. Credit: Tommi Sassi After more than 30 years, physicists…\n","protected":false},"author":3,"featured_media":170264,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[25],"tags":[97371,62570,492,159,67,132,97372,68],"class_list":{"0":"post-170263","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-physics","8":"tag-atomic-physics","9":"tag-nuclear-physics","10":"tag-physics","11":"tag-science","12":"tag-united-states","13":"tag-unitedstates","14":"tag-university-of-jyvaskyla","15":"tag-us"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@us\/115080580585622921","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/170263","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/comments?post=170263"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/170263\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media\/170264"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media?parent=170263"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/categories?post=170263"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/tags?post=170263"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}