Beyond the neutron drip line: The unbound oxygen isotopes O-25 and O-26

Summary, in English

The very neutron-rich oxygen isotopes O-25 and O-26 are investigated experimentally and theoretically. The unbound states are populated in an experiment performed at the R3B-LAND setup at GSI via proton-knockout reactions from F-26 and F-27 at relativistic energies around 442 and 414 MeV/nucleon, respectively. From the kinematically complete measurement of the decay into O-24 plus one or two neutrons, the O-25 ground-state energy and width are determined, and upper limits for the O-26 ground-state energy and lifetime are extracted. In addition, the results provide indications for an excited state in O-26 at around 4 MeV. The experimental findings are compared to theoretical shell-model calculations based on chiral two- and three-nucleon (3N) forces, including for the first time residual 3N forces, which are shown to be amplified as valence neutrons are added.

• Author: C. Caesar; J. Simonis; T. Adachi; Y. Aksyutina; J. Alcantara; S. Altstadt; H. Alvarez-Pol; N. Ashwood; T. Aumann; Vladimir Avdeichikov; M. Barr; S. Beceiro; D. Bemmerer; J. Benlliure; C. A. Bertulani; K. Boretzky; M. J. G. Borge; G. Burgunder; M. Caamano; E. Casarejos; W. Catford; Joakim Cederkäll; S. Chakraborty; M. Chartier; L. Chulkov; D. Cortina-Gil; U. Datta Pramanik; P. Diaz Fernandez; I. Dillmann; Z. Elekes; J. Enders; O. Ershova; A. Estrade; F. Farinon; L. M. Fraile; M. Freer; M. Freudenberger; H. O. U. Fynbo; D. Galaviz; H. Geissel; R. Gernhaeuser; Pavel Golubev; D. Gonzalez Diaz; J. Hagdahl; T. Heftrich; M. Heil; M. Heine; A. Heinz; A. Henriques; M. Holl; J. D. Holt; G. Ickert; A. Ignatov; Bo Jakobsson; H. T. Johansson; B. Jonson; N. Kalantar-Nayestanaki; R. Kanungo; A. Kelic-Heil; R. Knoebel; T. Kroell; R. Kruecken; J. Kurcewicz; M. Labiche; C. Langer; T. Le Bleis; R. Lemmon; O. Lepyoshkina; S. Lindberg; J. Machado; J. Marganiec; V. Maroussov; J. Menendez; M. Mostazo; A. Movsesyan; A. Najafi; T. Nilsson; C. Nociforo; V. Panin; A. Perea; S. Pietri; R. Plag; A. Prochazka; A. Rahaman; G. Rastrepina; R. Reifarth; G. Ribeiro; M. V. Ricciardi; C. Rigollet; K. Riisager; M. Roeder; D. Rossi; J. Sanchez del Rio; D. Savran; H. Scheit; A. Schwenk; H. Simon; O. Sorlin; V. Stoica; B. Streicher; J. Taylor; O. Tengblad; S. Terashima; R. Thies; Y. Togano; E. Uberseder; J. Van de Walle; P. Velho; V. Volkov; A. Wagner; F. Wamers; H. Weick; M. Weigand; C. Wheldon; G. Wilson; C. Wimmer; J. S. Winfield; P. Woods; D. Yakorev; M. V. Zhukov; A. Zilges; M. Zoric; K. Zuber
• Department/s: Nuclear physics
• Publishing year: 2013
• Language: English
• Publication/Series: Physical Review C (Nuclear Physics)
• Volume: 88
• Issue: 3
• Links: http://dx.doi.org/10.1103/PhysRevC.88.034313
• Document type: Journal article
• Publisher: American Physical Society
• Topic: Subatomic Physics
• Status: Published
• ISBN/ISSN/Other: ISSN: 0556-2813