{"paper":{"title":"Neutron skin and signature of the $N$ = 14 shell gap found from measured proton radii of $^{17-22}$N","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["nucl-th"],"primary_cat":"nucl-ex","authors_text":"A. Estrad\\'e, A. Evdokimov, A. Prochazka, B. Sitar, C. Nociforo, C. Scheidenberger, D. Cortina-Gil, F. Ameil, F. Farinon, G. Guastalla, G. Hagen, H. Geissel, H. J. Ong, H. Weick, I. Dillmann, I. Mukha, I. Tanihata, J. Atkinson, J. Kurcewicz, J. S. Winfield, J. Tanaka, J. Vargas, M. Marta, M. Mostazo, M. Takechi, P. Strmen, R. Janik, R. Kanungo, R. Knobel, S. Bagchi, S. Kaur, S. Pietri, S. R. Stroberg, S. Terashima, T. D. Morris, T. Suzuki, W. Horiuchi, Y. Ayyad, Y. Tanaka, Yu. A. Litvinov","submitted_at":"2019-01-28T14:51:00Z","abstract_excerpt":"A thick neutron skin emerges from the first determination of root mean square radii of the proton distributions for $^{17-22}$N from charge changing cross section measurements around 900$A$ MeV at GSI. Neutron halo effects are signaled for $^{22}$N from an increase in the proton and matter radii. The radii suggest an unconventional shell gap at $N$ = 14 arising from the attractive proton-neutron tensor interaction, in good agreement with shell model calculations. $Ab$ $initio$, in-medium similarity re-normalization group, calculations with a state-of-the-art chiral nucleon-nucleon and three-nu"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1901.09707","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":""},"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"}