{"paper":{"title":"Shape coexistence near the neutron number N=20: First identification of the E0 decay from the deformed 0^+_2 state in 30Mg","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"nucl-ex","authors_text":"D. Habs, H. Huebel, H. Mach, J.L. Egido, K. Heyde, K. Wimmer, L.M. Fraile, P.G. Thirolf, P. Hoff, P. Ring, R. Gernhaeuser, R. Hertenberger, R. Kruecken, R. Lutter, T. Kroell, T. Morgan, T.R. Rodriguez, U. Koester, V. Bildstein, W. Schwerdtfeger","submitted_at":"2008-08-02T14:52:46Z","abstract_excerpt":"The 1789 keV level in 30Mg was identified as the first excited 0^+ state by measuring its E0 transition to the ground state. The measured small value of rho^2(E0,0^+_2 --> 0^+_1) = 5.7(14) x 10^-3 implies a very small mixing of competing configurations with largely different intrinsic quadrupole deformation near N=20. Axially symmetric Beyond-Mean-Field configuration mixing calculations identify the ground state of 30Mg to be based on neutron configurations below the N=20 shell closure, while the excited 0^+ state mainly consists of a two neutrons excitated into the nu1 f_{7/2} orbital. Using "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0808.0264","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"}