Abstract
The shell closure at N=32 has been investigated by a first spectroscopy of the N=31 nucleus Ar49 at the Radioactive Isotope Beam Factory. Using the Ar50(p,pn) reaction channel in inverse kinematics, Ar50 projectiles at 217 MeV/nucleon impinged on a 150 mm long liquid hydrogen target, part of the MINOS device. Prompt deexcitation γ rays were measured with the NaI(Tl) array DALI2+. Reaction products were analyzed with the SAMURAI spectrometer, which allowed the measurement of the momentum distributions and angular momentum transfer. Data were compared to state-of-the-art theoretical predictions, including shell-model, energy-density functional, and ab initio calculations. An onset of collectivity is suggested besides the spherical configuration typical of a closed shell nucleus, such as for Ca52.
| Original language | English |
|---|---|
| Article number | 034312 |
| Journal | Physical Review C |
| Volume | 109 |
| Issue number | 3 |
| DOIs | |
| State | Published - Mar 2024 |
| Externally published | Yes |
Funding
We thank the RIKEN Nishina Center accelerator staff for their work in the primary beam delivery and the BigRIPS team for preparing the secondary beams. The development of MINOS has been supported by the European Research Council through the ERC Grant No. MINOS258567. B.D.L. and L.X.C. acknowledge support from the Vietnam Ministry of Science and Technology under Grant No. ĐTCB.01/21/VKHKTHN. M.G.-R. and A.M.M. acknowledge financial support by MCIN/AEI/10.13039/501100011033 under I + D + i Project No. PID2020-114687GB-I00 and under Grant No. IJC2020-043878-I (also funded by “European Union NextGenerationEU/PRTR”), by the Consejería de Economía, Conocimiento, Empresas y Universidad, Junta de Andalucía (Spain) and “ERDF-A Way of Making Europe” under PAIDI 2020 Project No. P20_01247, and by the European Social Fund and Junta de Andalucía (PAIDI 2020) under Grant No. DOC-01006. T.M. acknowledges the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (Grant Agreement No. 101020842) F.B. was supported by the RIKEN Special Postdoctoral Researcher Program. Y.L.S. acknowledges the support of a Marie Skłodowska-Curie Individual Fellowship (H2020-MSCAIF-2015-705023) from the European Union. I.G. was supported by HIC for FAIR and Croatian Science Foundation. R.-B.G. is supported by the Deutsche Forschungsgemeinschaft (DFG) under Grant No. BL 1513/1-1. K.I.H., D.K., and S.Y.P. acknowledge support from an IBS grant funded by the Korean government (No. IBS-R031-D1). P.K. and V.W. were supported in part by the BMBF Grants No. 05P19RDFN1, No. 05P21RDFN1, and No. HGS-HIRe. D.So. was supported by the National Research, Development and Innovation Fund of Hungary via Projects No. K128947 and No. TKP2021-NKTA-42. P.-A.S. acknowledges support from BMBF under Grant No. NuSTAR.DA 05P15RDFN1 and Contract No. PN 23.21.01.06 sponsored by the Romanian Ministry of Research, Innovation and Digitalization. This work was supported in part by JSPS KAKENHI Grants No. JP16H02179, No. JP18H05404, and No. JP20K03981. J.D.H. acknowledges support from NSERC, the National Research Council Canada, and the Arthur B. McDonald Canadian Astroparticle Physics Research Institute. T.M. acknowledges support from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation), Project-ID 279384907–SFB 1245. This work was supported by the Office of Nuclear Physics, U.S. Department of Energy, under Grant No. de-sc0018223 (NUCLEI SciDAC-4 Collaboration) and the FieldWork Proposal No. ERKBP72 at Oak Ridge National Laboratory (ORNL). Computer time was provided by the Innovative and Novel Computational Impact on Theory and Experiment (INCITE) program. This research 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-AC05-00OR22725. GGF calculations were performed by using HPC resources from GENCI-TGCC (Contracts No. A0090507392 and No. A0110513012) and at the DiRAC DiAL system at the University of Leicester (funded by the UK BEIS via STFC Capital Grants No. ST/K000373/1 and No. ST/R002363/1 and STFC DiRAC Operations Grant No. ST/R001014/1) and at the National Energy Research Scientific Computing Center (NERSC), a U.S. Department of Energy User Facility using Awards No. NP-ERCAP0020946 and No. NP-ERCAP0024959. This work was supported by the United Kingdom Science and Technology Facilities Council (STFC) under Grant No. ST/L005816/1 and in part by the NSERC Grants No. SAPIN-2016-00033, No. SAPIN-2018-00027, and No. RGPAS-2018-522453. TRIUMF receives federal funding via a contribution agreement with the National Research Council of Canada. J.D.H., B.S.H., and T.M. thank S. R. Stroberg for the imsrg+ + code used to perform the VS-IMSRG calculations . The valence-space diagonalization of the VS-IMSRG calculations were done with the kshell code . The VS-IMSRG computations were performed with an allocation of computing resources on Cedar at WestGrid and Compute Canada, and on the Oak Cluster at TRIUMF managed by the University of British Columbia department of Advanced Research Computing (ARC). N.T.T.P is funded by the University of Science, VNU-HCM under Grant No. T2021-02.