{"paper":{"title":"High-precision measurement of the kaonic hydrogen 1s level shift and width with SIDDHARTA-2","license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","headline":"","cross_cats":["physics.atom-ph"],"primary_cat":"nucl-ex","authors_text":"A. Buttacavoli, A. Clozza, A. Khreptak, A. Scordo, A. Spallone, C. Amsler, C. Curceanu, C. Fiorini, C. Guaraldo, C. Milardi, D. Bosnar, D. Sirghi, F. Artibani, F. Clozza, F. Napolitano, F. Principato, F. Sgaramella, F. Sirghi, G. Borghi, H. Ohnishi, I. Fri\\v{s}\\v{c}i\\'c, J. Marton, J. Zmeskal, K. Dulski, K. Piscicchia, K. Toho, L. Abbene, L. De Paolis, M. A. Iliescu, M. Bazzi, M. Bragadireanu, M. Carminati, M. Iwasaki, M. Silarski, M. Skurzok, M. T\\\"uchler, O. Vazquez Doce, P. Moskal, R. Del Grande, S. Manti","submitted_at":"2026-07-15T15:40:02Z","abstract_excerpt":"Kaonic atoms provide a unique experimental probe of strong interaction in the low-energy regime. In particular, the strong-interaction-induced shift ($\\varepsilon_{1\\text{s}}$) and width ($\\Gamma_{1\\text{s}}$) of kaonic hydrogen directly constrain the low-energy antikaon-nucleon ($\\bar{K}N$) interaction at threshold and the theoretical description of the $\\Lambda$(1405) resonance. We report a new high-precision measurement of kaonic hydrogen X-ray transitions performed by the SIDDHARTA-2 experiment at the DA$\\Phi$NE collider (INFN-LNF), based on an integrated luminosity of 237 pb$^{-1}$. The e"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2607.13952","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2607.13952/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}