Suchergebnisse

9 pags., 3 figs. ; The low-lying level structure of V63 was studied for the first time by the inelastic proton scattering and the proton knock-out reaction in inverse kinematics. The comparison of the newly observed γ-ray transitions at 696(8) keV and 889(16) keV with our shell-model calculations using the Lenzi-Nowacki-Poves-Sieja interaction established two excited states proposed to be the first 11/2- and 9/2- levels. The (p,p′) excitation cross sections were analyzed by the coupled channel formalism assuming pure quadrupole as well as quadrupole+hexadecapole deformations. This resulted in large deformation parameters placing V63 in the island of inversion located below Ni68. ; We are very grateful to the RIKEN Nishina Center accelerator staff for providing the stable beam and to the BigRIPS team for the smooth operation of the secondary beams. The development of the MINOS device has been supported by the European Research Council through the ERC Grant No. MINOS-258567. F.B. was supported by the RIKEN Special Postdoctoral Researcher Program. K.O. acknowledges the support by Grant-in-Aid for Scientific Research JP16K05352. Y.U. acknowledges the support by Grant-in-Aid for Scientific Research No. 20K03981. Y.L.S. acknowledges the support of Marie Skłodowska-Curie Individual Fellowship (H2020-MSCA-IF-2015-705023) from the European Union and the support from the Helmholtz International Center for FAIR. H.N.L. acknowledges the support from the Enhanced Eurotalents program (PCOFUND-GA-2013-600382) co-funded by CEA and the European Union. T.A., C.L., D.R., H.T., V.W., L.Z., H.N.L., V.W., and A.O. acknowledge the support from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) Project No. 279384907-SFB 1245. R.B.G. acknowledges the support from the DFG under Grant No. BL 1513/1-1. Y.L.S. and A.O. acknowledge the support from the Alexander von Humboldt Foundation. B.D.L. and L.X.C. acknowledge the support from the Vietnam Ministry of Science and Technology under Grant No. ĐTCB.01/21/VKHKTHN. I.G. has been supported by HIC for FAIR and HRZZ under Projects No. 1257 and No. 7194. F.B. acknowledge the support from the RIKEN Special Postdoctoral Researcher Program. D.S. and Z.E. were supported by Projects No. GINOP-2.3.3-15-2016-00034 and K128947. V.V. acknowledges support from the Spanish Ministerio de Economía y Competitividad under Contract No. FPA2017-84756-C4-2-P. V.W. and P.K. acknowledge the support from BMBF Grants No. 05P15RDFN1 and No. 05P19RDFN1. P.K. acknowledges support from HGSHIRe. This work was also supported by NKFIH (114454) and by Swedish Research Council under Grants No. 621-2014-5558 and No. 2019-04880. K.I.H., D.K., and S.Y.P. acknowledge the support from the IBS grant funded by the Korea government (No. IBS-R031-D1). T.N. and Y.K. acknowledge the support by JSPS Grant-in-Aid for Scientific Research Grants No. JP16H02179, No. JP18H05404, and No. JP21H04465. ; Peer reviewed

8 pags., 4 figs., 3 tabs. ; The nuclear structure of 51Ar, an uncharted territory so far, was studied by the (p,2p) reaction using γ-ray spectroscopy for the bound states and the invariant mass method for the unbound states. Two peaks were detected in the γ-ray spectrum and six peaks were observed in the 50Ar+n relative energy spectrum. Comparing the results to our shell-model calculations, two bound and six unbound states were established. Three of the unbound states could only be placed tentatively due to the low number of counts in the relative energy spectrum of events associated with the decay through the first excited state of 50Ar. The low cross sections populating the two bound states of 51Ar could be interpreted as a clear signature for the presence of significant subshell closures at neutron numbers 32 and 34 in argon isotopes. It was also revealed that due to the two valence holes, unbound collective states coexist with individual-particle states in 51Ar. ; We are very grateful to the RIKEN Nishina Center accelerator staff for providing the stable beam and to the BigRIPS team for the smooth operation of the secondary beams. The development of the MINOS device has been supported by the European Research Council through the ERC Grant No. MINOS-258567. F. B. was supported by the RIKEN Special Postdoctoral Researcher Program. K. O. acknowledges the support by Grant-in-Aid for Scientific Research JP16K05352. Y. U. acknowledges the support by Grant-in-Aid for Scientific Research 20K03981. Y. L. S. acknowledges the support of Marie Skłodowska-Curie Individual Fellowship (H2020-MSCA-IF-2015-705023) from the European Union and the support from the Helmholtz International Center for FAIR. H. N. L. acknowledges the support from the Enhanced Eurotalents program (PCOFUND-GA-2013-600382) co-funded by CEA and the European Union. T. A., C. L., D. R., H. T., V. W., L. Z., H. N. L., V. W. and A. O. acknowledge the support from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) Project No. 279384907-SFB 1245. R. B. G. acknowledges the support from the DFG under Grant No. BL 1513/1-1. Y. L. S. and A. O. acknowledge the support from the Alexander von Humboldt Foundation. B. D. L. and L. X. C. acknowledge the support from the Vietnam Ministry of Science and Technology under Grant No. ĐTCB.01/21/VKHKTHN. I. G. has been supported by HIC for FAIR and HRZZ under project No. 1257 and 7194. K. I. H., D. K. and S. Y. P. acknowledge the support from the NRF grant funded by the Korea government (No. 2017R1A2B2012382 and 2019M7A1A1033186). F. B. acknowledge the support from the RIKEN Special Postdoctoral Researcher Program. D. S. and Z. E. were supported by projects No. GINOP-2.3.3-15-2016-00034 and No. K128947. V. V. acknowledges support from the Spanish Ministerio de Economía y Competitividad under Contract No. FPA2017-84756-C4-2-P. V. W. and P. K. acknowledge the support from BMBF grants 05P15RDFN1 and 05P19RDFN1. P. K. acknowledges support from HGS-HIRe. This work was also supported by NKFIH (114454). ; Peer reviewed

7 pags., 3 figs. ; Direct proton-knockout reactions of ^{55}Sc at ∼220 MeV/nucleon were studied at the RIKEN Radioactive Isotope Beam Factory. Populated states of ^{54}Ca were investigated through γ-ray and invariant-mass spectroscopy. Level energies were calculated from the nuclear shell model employing a phenomenological internucleon interaction. Theoretical cross sections to states were calculated from distorted-wave impulse approximation estimates multiplied by the shell model spectroscopic factors, which describe the wave function overlap of the ^{55}Sc ground state with states in ^{54}Ca. Despite the calculations showing a significant amplitude of excited neutron configurations in the ground-state of ^{55}Sc, valence proton removals populated predominantly the ground state of ^{54}Ca. This counterintuitive result is attributed to pairing effects leading to a dominance of the ground-state spectroscopic factor. Owing to the ubiquity of the pairing interaction, this argument should be generally applicable to direct knockout reactions from odd-even to even-even nuclei. ; Our gratitude is extended to the RIKEN Nishina Center accelerator staff for the stable and high-intensity transport of the Zn primary beam, and the BigRIPS team for their preparation of the magnetic settings of the secondary beam. F. B. is supported by the RIKEN Special Postdoctoral Researcher Program. S. C. acknowledges support from the IPA program at the RIKEN Nishina Center. K. O. and K. Y. acknowledge the support from Grants-in-Aid of the Japan Society for the Promotion of Science under Grants No. JP16K05352. This work was supported by JSPS KAKENHI Grants No. JP16H02179 and No. JP18H05404, the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Grant No. BL 1513/1-1 HGS-HIRe and Project-ID 279384907-SFB 1245 and the GSI-TU Darmstadt cooperation agreement, the BMBF (Grant No. 05P19RDFN1), Swedish Research Council under Grants No. 621-2014-5558 and No. 2019-04880. L. X. C. and B. D. L. are supported by the Vietnam MOST via the Physics Development Program Grant No. TĐLCN.25/18. D. So. was supported by the European Regional Development Fund Contract No. GINOP-2.3.3-15-2016-00034 and the National Research, Development and Innovation Fund of Hungary via Project No. K128947. L. S, K. I. H., D. K., and S. Y. P. acknowledge the support from the IBS grant funded by the Korea government (No. IBS-R031-D1). ; Peer reviewed

7 pags., 3 figs., 1 tab. ; States in the N = 35 and 37 isotopes 55,57Ca have been populated by direct proton-induced nucleon removal reactions from 56,58Sc and 56Ca beams at the RIBF. In addition, the (p, 2p) quasi-free single- proton removal reaction from 56Ca was studied. Excited states in 55K, 55Ca, and 57Ca were established for the first time via in-beam γ -ray spectroscopy. Results for the proton and neutron removal reactions from 56Ca to states in 55K and 55Ca for the level energies, excited state lifetimes, and exclusive cross sections agree well with state-of-the-art theoretical calculations using different approaches. The observation of a short-lived state in 57Ca suggests a transition in the calcium isotopic chain from single-particle dominated states at N = 35 to collective excitations at N = 37. ; We would like to thank the RIKEN accelerator and BigRIPS teams for providing the high intensity beams. T.K. acknowledges support by RIKEN Junior Research Associate Program. K.W. acknowledges support from the Spanish Ministerio de Ciencia, Innovación y Universidades RYC-2017-22007. RIUMF receives funding via a contribution through the National Research Council of Canada. J.D.H is further supported by NSERC under grants SAPIN-2018-00027 and RGPAS-2018-522453. 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.S. and Y.U. acknowledge valuable support by "Priority Issue on post-K computer" and KAKENHI grant 20K03981 and 17K05433. C.B. was supported by the UK Science and Technology Facilities Council (STFC) through grants No. ST/L005816/1 and No. ST/V001108/1. SCGF calculations were per- formed by using HPC resources from GENCI-TGCC, France (Contract No. A009057392) and at the DiRAC DiAL system at the University of Leicester, UK, (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). I.M. was supported by the RIKEN IPA program, F.B. by the RIKEN Special Postdoctoral Researche Program. D.S. acknowledges support from the European Regional Development Fund contract No. GINOP-2.3.3-15-2016-00034 and the National Research, Development and Innovation Fund of Hungary via Project No. K128947. K. I. H., D. K., and S. Y. P. acknowledge the support from the IBS grant funded by the Korea government (No. IBS-R031-D1). The work was further supported by JSPS KAKENHI Grant Nos. JP16H02179, JP18H05404, JP19H00679, and JP21H01114 and the Deutsche Forschungsgemeinschaft (DFG) under Grant No. BL 1513/1-1 ; Peer reviewed