Physics Letters B (Apr 2018)
Re-examining the transition into the N=20 island of inversion: Structure of 30Mg
- B. Fernández-Domínguez,
- B. Pietras,
- W.N. Catford,
- N.A. Orr,
- M. Petri,
- M. Chartier,
- S. Paschalis,
- N. Patterson,
- J.S. Thomas,
- M. Caamaño,
- T. Otsuka,
- A. Poves,
- N. Tsunoda,
- N.L. Achouri,
- J.-C. Angélique,
- N.I. Ashwood,
- A. Banu,
- B. Bastin,
- R. Borcea,
- J. Brown,
- F. Delaunay,
- S. Franchoo,
- M. Freer,
- L. Gaudefroy,
- S. Heil,
- M. Labiche,
- B. Laurent,
- R.C. Lemmon,
- A.O. Macchiavelli,
- F. Negoita,
- E.S. Paul,
- C. Rodríguez-Tajes,
- P. Roussel-Chomaz,
- M. Staniou,
- M.J. Taylor,
- L. Trache,
- G.L. Wilson
Affiliations
- B. Fernández-Domínguez
- Department of Physics, University of Liverpool, Liverpool, L69 7ZE, UK; LPC-Caen, IN2P3/CNRS, ENSICAEN, UNICAEN et Normandie Université, 14050 Caen Cedex, France; Universidade de Santiago de Compostela, 15754 Santiago de Compostela, Spain; Corresponding author.
- B. Pietras
- Department of Physics, University of Liverpool, Liverpool, L69 7ZE, UK
- W.N. Catford
- Department of Physics, University of Surrey, Guildford GU2 5XH, UK
- N.A. Orr
- LPC-Caen, IN2P3/CNRS, ENSICAEN, UNICAEN et Normandie Université, 14050 Caen Cedex, France
- M. Petri
- Department of Physics, University of Liverpool, Liverpool, L69 7ZE, UK; Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt, Germany; Department of Physics, University of York, Heslington, York YO10 5DD, UK
- M. Chartier
- Department of Physics, University of Liverpool, Liverpool, L69 7ZE, UK
- S. Paschalis
- Department of Physics, University of Liverpool, Liverpool, L69 7ZE, UK; Department of Physics, University of York, Heslington, York YO10 5DD, UK
- N. Patterson
- Department of Physics, University of Surrey, Guildford GU2 5XH, UK
- J.S. Thomas
- Department of Physics, University of Surrey, Guildford GU2 5XH, UK
- M. Caamaño
- Universidade de Santiago de Compostela, 15754 Santiago de Compostela, Spain
- T. Otsuka
- CNS, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
- A. Poves
- Departamento de Fisica Teórica and IFT-UAM/CSIC, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
- N. Tsunoda
- CNS, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
- N.L. Achouri
- LPC-Caen, IN2P3/CNRS, ENSICAEN, UNICAEN et Normandie Université, 14050 Caen Cedex, France
- J.-C. Angélique
- LPC-Caen, IN2P3/CNRS, ENSICAEN, UNICAEN et Normandie Université, 14050 Caen Cedex, France
- N.I. Ashwood
- School of Physics and Astronomy, University of Birmingham, Birmingham, B15 2TT, UK
- A. Banu
- Cyclotron Institute, Texas A&M University, College Station, TX-77843, USA
- B. Bastin
- LPC-Caen, IN2P3/CNRS, ENSICAEN, UNICAEN et Normandie Université, 14050 Caen Cedex, France
- R. Borcea
- IFIN-HH Bucharest-Magurele, RO-077125, Romania
- J. Brown
- Department of Physics, University of York, Heslington, York YO10 5DD, UK
- F. Delaunay
- LPC-Caen, IN2P3/CNRS, ENSICAEN, UNICAEN et Normandie Université, 14050 Caen Cedex, France
- S. Franchoo
- IPN-Orsay, 91406 Orsay, France
- M. Freer
- School of Physics and Astronomy, University of Birmingham, Birmingham, B15 2TT, UK
- L. Gaudefroy
- GANIL, CEA/DRF–CNRS/IN2P3, BP 55027, 14076 Caen Cedex 05, France
- S. Heil
- Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt, Germany
- M. Labiche
- Nuclear Structure Group, CCLRC Daresbury Laboratory, Daresbury, Warrington WA4 4AD, UK
- B. Laurent
- LPC-Caen, IN2P3/CNRS, ENSICAEN, UNICAEN et Normandie Université, 14050 Caen Cedex, France
- R.C. Lemmon
- Nuclear Structure Group, CCLRC Daresbury Laboratory, Daresbury, Warrington WA4 4AD, UK
- A.O. Macchiavelli
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- F. Negoita
- IFIN-HH Bucharest-Magurele, RO-077125, Romania
- E.S. Paul
- Department of Physics, University of Liverpool, Liverpool, L69 7ZE, UK
- C. Rodríguez-Tajes
- GANIL, CEA/DRF–CNRS/IN2P3, BP 55027, 14076 Caen Cedex 05, France
- P. Roussel-Chomaz
- GANIL, CEA/DRF–CNRS/IN2P3, BP 55027, 14076 Caen Cedex 05, France
- M. Staniou
- IFIN-HH Bucharest-Magurele, RO-077125, Romania
- M.J. Taylor
- Department of Physics, University of York, Heslington, York YO10 5DD, UK
- L. Trache
- Cyclotron Institute, Texas A&M University, College Station, TX-77843, USA; IFIN-HH Bucharest-Magurele, RO-077125, Romania
- G.L. Wilson
- Department of Physics, University of Surrey, Guildford GU2 5XH, UK
- Journal volume & issue
-
Vol. 779
pp. 124 – 129
Abstract
Intermediate energy single-neutron removal from 31Mg has been employed to investigate the transition into the N=20 island of inversion. Levels up to 5 MeV excitation energy in 30Mg were populated and spin-parity assignments were inferred from the corresponding longitudinal momentum distributions and γ-ray decay scheme. Comparison with eikonal-model calculations also permitted spectroscopic factors to be deduced. Surprisingly, the 02+ level in 30Mg was found to have a strength much weaker than expected in the conventional picture of a predominantly 2p−2h intruder configuration having a large overlap with the deformed 31Mg ground state. In addition, negative parity levels were identified for the first time in 30Mg, one of which is located at low excitation energy. The results are discussed in the light of shell-model calculations employing two newly developed approaches with markedly different descriptions of the structure of 30Mg. It is concluded that the cross-shell effects in the region of the island of inversion at Z=12 are considerably more complex than previously thought and that np−nh configurations play a major role in the structure of 30Mg.
