{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,11]],"date-time":"2026-01-11T00:50:56Z","timestamp":1768092656211,"version":"3.49.0"},"reference-count":30,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2020,4,4]],"date-time":"2020-04-04T00:00:00Z","timestamp":1585958400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Symmetry"],"abstract":"<jats:p>Kaonic atoms measure the antikaon-nucleus interaction at almost zero relative energy, allowing one to determine basic low-energy quantum chromodynamics (QCD) quantities, namely, the antikaon-nucleon (    K \u00af    N) scattering lengths. The latter are important for extracting the sigma terms which are built on the symmetry breaking part of the Hamiltonian, thereby providing a measure of chiral and SU(3) symmetries breaking. After discussing the sigma terms and their relations to the kaonic atoms, we describe the most precise measurement in the literature of kaonic hydrogen, performed at LNF-INFN by the SIDDHARTA experiment. Kaonic deuterium is still to be measured, and two experiments are planned. The first, SIDDHARTA-2 at LNF-INFN was installed on DA   \u03a6   NE in spring 2019 and will collect data in 2020. The second, E57 at J-PARC, will become operative in 2021.<\/jats:p>","DOI":"10.3390\/sym12040547","type":"journal-article","created":{"date-parts":[[2020,4,9]],"date-time":"2020-04-09T03:40:19Z","timestamp":1586403619000},"page":"547","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":18,"title":["Kaonic Atoms to Investigate Global Symmetry Breaking"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1990-0127","authenticated-orcid":false,"given":"Catalina","family":"Curceanu","sequence":"first","affiliation":[{"name":"INFN, Laboratori Nazionali di Frascati, Frascati, 00044 Roma, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8923-3438","authenticated-orcid":false,"given":"Carlo","family":"Guaraldo","sequence":"additional","affiliation":[{"name":"INFN, Laboratori Nazionali di Frascati, Frascati, 00044 Roma, Italy"}]},{"given":"Diana","family":"Sirghi","sequence":"additional","affiliation":[{"name":"INFN, Laboratori Nazionali di Frascati, Frascati, 00044 Roma, Italy"},{"name":"Horia Hulubei National Institute of Physics and Nuclear Engineering, IFIN-HH, Magurele 077125, Romania"}]},{"given":"Aidin","family":"Amirkhani","sequence":"additional","affiliation":[{"name":"Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria and INFN Sezione di Milano, 20133 Milano, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3269-3716","authenticated-orcid":false,"given":"Ata","family":"Baniahmad","sequence":"additional","affiliation":[{"name":"Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria and INFN Sezione di Milano, 20133 Milano, Italy"}]},{"given":"Massimiliano","family":"Bazzi","sequence":"additional","affiliation":[{"name":"INFN, Laboratori Nazionali di Frascati, Frascati, 00044 Roma, Italy"}]},{"given":"Giovanni","family":"Bellotti","sequence":"additional","affiliation":[{"name":"Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria and INFN Sezione di Milano, 20133 Milano, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4784-393X","authenticated-orcid":false,"given":"Damir","family":"Bosnar","sequence":"additional","affiliation":[{"name":"Department of Physics, Faculty of Science, University of Zagreb, 10000 Zagreb, Croatia"}]},{"given":"Mario","family":"Bragadireanu","sequence":"additional","affiliation":[{"name":"Horia Hulubei National Institute of Physics and Nuclear Engineering, IFIN-HH, Magurele 077125, Romania"}]},{"given":"Michael","family":"Cargnelli","sequence":"additional","affiliation":[{"name":"Stefan-Meyer-Institut f\u00fcr Subatomare Physik, 1090 Vienna, Austria"}]},{"given":"Marco","family":"Carminati","sequence":"additional","affiliation":[{"name":"Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria and INFN Sezione di Milano, 20133 Milano, Italy"}]},{"given":"Alberto","family":"Clozza","sequence":"additional","affiliation":[{"name":"INFN, Laboratori Nazionali di Frascati, Frascati, 00044 Roma, Italy"}]},{"given":"Luca","family":"De Paolis","sequence":"additional","affiliation":[{"name":"INFN, Laboratori Nazionali di Frascati, Frascati, 00044 Roma, Italy"}]},{"given":"Raffaele","family":"Del Grande","sequence":"additional","affiliation":[{"name":"INFN, Laboratori Nazionali di Frascati, Frascati, 00044 Roma, Italy"},{"name":"Museo Storico della Fisica e Centro Studi e Ricerche \u201cEnrico Fermi\u201d, 00184 Roma, Italy"}]},{"given":"Carlo","family":"Fiorini","sequence":"additional","affiliation":[{"name":"Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria and INFN Sezione di Milano, 20133 Milano, Italy"}]},{"given":"Mihail","family":"Iliescu","sequence":"additional","affiliation":[{"name":"INFN, Laboratori Nazionali di Frascati, Frascati, 00044 Roma, Italy"}]},{"given":"Masahiko","family":"Iwasaki","sequence":"additional","affiliation":[{"name":"RIKEN, Tokyo 351-0198, Japan"}]},{"given":"Pietro","family":"King","sequence":"additional","affiliation":[{"name":"Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria and INFN Sezione di Milano, 20133 Milano, Italy"}]},{"given":"Paolo","family":"Levi Sandri","sequence":"additional","affiliation":[{"name":"INFN, Laboratori Nazionali di Frascati, Frascati, 00044 Roma, Italy"}]},{"given":"Johann","family":"Marton","sequence":"additional","affiliation":[{"name":"Stefan-Meyer-Institut f\u00fcr Subatomare Physik, 1090 Vienna, Austria"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2315-2379","authenticated-orcid":false,"given":"Marco","family":"Miliucci","sequence":"additional","affiliation":[{"name":"INFN, Laboratori Nazionali di Frascati, Frascati, 00044 Roma, Italy"}]},{"given":"Pawe\u0142","family":"Moskal","sequence":"additional","affiliation":[{"name":"The M. Smoluchowski Institute of Physics, Jagiellonian University, 30-348 Krak\u00f3w, Poland"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5953-9479","authenticated-orcid":false,"given":"Szymon","family":"Nied\u017awiecki","sequence":"additional","affiliation":[{"name":"The M. Smoluchowski Institute of Physics, Jagiellonian University, 30-348 Krak\u00f3w, Poland"}]},{"given":"Shinji","family":"Okada","sequence":"additional","affiliation":[{"name":"RIKEN, Tokyo 351-0198, Japan"}]},{"given":"Kristian","family":"Piscicchia","sequence":"additional","affiliation":[{"name":"INFN, Laboratori Nazionali di Frascati, Frascati, 00044 Roma, Italy"},{"name":"Museo Storico della Fisica e Centro Studi e Ricerche \u201cEnrico Fermi\u201d, 00184 Roma, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7703-7050","authenticated-orcid":false,"given":"Alessandro","family":"Scordo","sequence":"additional","affiliation":[{"name":"INFN, Laboratori Nazionali di Frascati, Frascati, 00044 Roma, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2206-0963","authenticated-orcid":false,"given":"Micha\u0142","family":"Silarski","sequence":"additional","affiliation":[{"name":"The M. Smoluchowski Institute of Physics, Jagiellonian University, 30-348 Krak\u00f3w, Poland"}]},{"given":"Florin","family":"Sirghi","sequence":"additional","affiliation":[{"name":"INFN, Laboratori Nazionali di Frascati, Frascati, 00044 Roma, Italy"},{"name":"Horia Hulubei National Institute of Physics and Nuclear Engineering, IFIN-HH, Magurele 077125, Romania"}]},{"given":"Magdalena","family":"Skurzok","sequence":"additional","affiliation":[{"name":"INFN, Laboratori Nazionali di Frascati, Frascati, 00044 Roma, Italy"},{"name":"The M. Smoluchowski Institute of Physics, Jagiellonian University, 30-348 Krak\u00f3w, Poland"}]},{"given":"Antonio","family":"Spallone","sequence":"additional","affiliation":[{"name":"INFN, Laboratori Nazionali di Frascati, Frascati, 00044 Roma, Italy"}]},{"given":"Marlene","family":"T\u00fcchler","sequence":"additional","affiliation":[{"name":"Stefan-Meyer-Institut f\u00fcr Subatomare Physik, 1090 Vienna, Austria"}]},{"given":"Gianlorenzo","family":"Utica","sequence":"additional","affiliation":[{"name":"Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria and INFN Sezione di Milano, 20133 Milano, Italy"}]},{"given":"Oton","family":"Vazquez Doce","sequence":"additional","affiliation":[{"name":"INFN, Laboratori Nazionali di Frascati, Frascati, 00044 Roma, Italy"},{"name":"Excellence Cluster Universe, Technische Universi\u00e4t M\u00fcnchen, 85748 Garching, Germany"}]},{"given":"Johann","family":"Zmeskal","sequence":"additional","affiliation":[{"name":"Stefan-Meyer-Institut f\u00fcr Subatomare Physik, 1090 Vienna, Austria"}]}],"member":"1968","published-online":{"date-parts":[[2020,4,4]]},"reference":[{"key":"ref_1","first-page":"643","article-title":"The DEAR physics programme","volume":"XVI","author":"Guaraldo","year":"1999","journal-title":"Phys. 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