Suchergebnisse

7 pags., 3 figs., 1 tab. -- Open Access funded by Creative Commons Atribution Licence 4.0 ; The first γ-ray spectroscopy of Ar52, with the neutron number N=34, was measured using the K53(p,2p) one-proton removal reaction at ∼210 MeV/u at the RIBF facility. The 21+ excitation energy is found at 1656(18) keV, the highest among the Ar isotopes with N>20. This result is the first experimental signature of the persistence of the N=34 subshell closure beyond Ca54, i.e., below the magic proton number Z=20. Shell-model calculations with phenomenological and chiral-effective-field-theory interactions both reproduce the measured 21+ systematics of neutron-rich Ar isotopes, and support a N=34 subshell closure in Ar52. ; We thank the RIKEN Nishina Center accelerator staff for their work in the primary beam delivery and the Big RIP Steam for preparing the secondary beams. The development of MINOS has been supported by the European Research Council through the ERC Grant No. MINOS 258567. Acknowledges the support from the Enhanced Eurotalents program (PCOFUND-GA-2013-600382) co-funded by CEA and the European Union. H.N.L., A.O. and A.S. acknowledge the support from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - Project No. 279384907- SFB 1245. C.A.B. acknowledges support from the U.S. NSF Grant No. 1415656 and the U.S. DOE Grant No.DE-FG02-08ER41533.J.D.H.and R.S.acknowledge the support from NSERC and the National Research Council Canada. Y.L.S. acknowledges the support of Marie Skłodowska-Curie Individual Fellowship (H2020-MSCAIF-2015-705023) from the European Union. I.G. has been supported by HIC for FAIR andCroatianScienceFoundation. L.X.C. and B.D.L. have been supported by the Vietnam MOST through the Physics Development Program Grant No. ĐTĐLCN.25/18. K.I.H., D.K. and S.Y.P. have been supported by the NRF grant funded by the Korea government (No. 2017R1A2B2012382 and 2018R1A5A1025563). This work was supported in part by JSPS KAKENHI Grant No. 16H02179, MEXT KAKENHI Grants No. 24105005 and No. 18H05404. This work was also supported by the Office of Nuclear Physics,U.S.Department of Energy,under Grants No.de-sc 0018223 (NUCLEISciDAC-4collaboration) and the Field Work Proposal ERKBP72 at Oak Ridge National Laboratory (ORNL). Computer time was provided by the Innovative and Novel Computational Impact on Theory and Experiment (INCITE) program. Thisresearch used resources of the Oak Ridge Leadership Computing Facility located at ORNL, which is supported by the Office of Science of the Department of Energy under Contract No. DE-AC0500OR22725.

7 pags. 4 figs. ; Fifty-five inclusive single nucleon-removal cross sections from medium mass neutron-rich nuclei impinging on a hydrogen target at ∼250 MeV/nucleon are measured at the RIKEN Radioactive Isotope Beam Factory. Systematically higher cross sections are found for proton removal from nuclei with an even number of protons as compared to odd-proton number projectiles for a given neutron separation energy. Neutron removal cross sections display no even-odd splitting, contrary to nuclear cascade model predictions. Both effects are understood through simple considerations of neutron separation energies and bound state level densities originating in pairing correlations in the daughter nuclei. These conclusions are supported by comparison with semimicroscopic model predictions, highlighting the enhanced role of low-lying level densities in nucleon-removal cross sections from loosely bound nuclei. ; We express our gratitude to the RIKEN Nishina Center accelerator staff for providing the stable and high-intensity uranium beam . A. O. thanks the European Research Council for its support through ERC Grant No. MINOS-258567, the Japanese Society for the Promotion of Science for the long-term fellowship L-13520, the German DFG SFB Grant No. 1245, and the Alexander von Humboldt Foundation. C. S. acknowledges support by the IPA program at the RIKEN Nishina Center. C. A. B. acknowledges support by U.S. Department of Energy Grant No. DE-FG02- 08ER41533 and U.S. National Science Foundation Grant No. 1415656. J. L. R.-S. acknowledges support by the Regional Government of Galicia under the program of postdoctoral fellowships. K. M. acknowledges support from German BMBF Grant No. 05P15PKFNA. M. L. C., M. L., and V. W. acknowledge support from German BMBF Grants No. 05P12RDFN8, No. 05P15RDFN1, and No. 05P12RDFN8, as well as DFG Grant No. SFB 1245. L. X. C. and B. D. L. are supported by the Vietnam MOST through Physics Development Program Grant No. ĐTĐLCN.25/18 and acknowledge the Radioactive Isotope Physics Laboratory of the RIKEN Nishina Center for supporting their stay during the experiment. A. J. and V. V. acknowledge support from the Spanish Ministerio de Economía y Competitividad under Contract No. FPA2014-57196-C5-4-P. U.K. participants acknowledge support from the Science and Technology Facilities Council (STFC). Collaborators from I. M. P. were supported by the National Natural Science Foundation of China and the Chinese Academy of Sciences.

New experimental data for dissociation of relativistic 17Ne projectiles incident on targets of lead, carbon, and polyethylene targets at GSI are presented. Special attention is paid to the excitation and decay of narrow resonant states in 17Ne. Distributions of internal energy in the 15O +p +pthree-body system have been determined together with angular and partial-energy correlations between the decay products in different energy regions. The analysis was done using existing experimental data on 17Ne and its mirror nucleus 17N. The isobaric multiplet mass equation is used for assignment of observed resonances and their spins and parities. A combination of data from the heavy and light targets yielded cross sections and transition probabilities for the Coulomb excitations of the narrow resonant states. The resulting transition probabilities provide information relevant for a better understanding of the 17Ne structure. ; This project is supported by NAVI, GSI-TU Darmstadt cooperation, HIC for FAIR, EMMI and BMBF. C.A.B. acknowledges support from the U.S. NSF Grant No. 1415655, and U.S. DOE grant No. DEFG02- 08ER41533. The work was also supported by the Spanish government grant FPA2012-32443 and the Swedish Research Council ; SI