Physics Letters B (Nov 2022)
Experimental observation of the M1 scissors mode in 254No
- F.L. Bello Garrote,
- A. Lopez-Martens,
- A.C. Larsen,
- I. Deloncle,
- S. Péru,
- F. Zeiser,
- P.T. Greenlees,
- B.V. Kheswa,
- K. Auranen,
- D.L. Bleuel,
- D.M. Cox,
- L. Crespo Campo,
- F. Giacoppo,
- A. Görgen,
- T. Grahn,
- M. Guttormsen,
- T.W. Hagen,
- L. Harkness-Brennan,
- K. Hauschild,
- G. Henning,
- R.-D. Herzberg,
- R. Julin,
- S. Juutinen,
- T.A. Laplace,
- M. Leino,
- J.E. Midtbø,
- V. Modamio,
- J. Pakarinen,
- P. Papadakis,
- J. Partanen,
- T. Renstrøm,
- K. Rezynkina,
- M. Sandzelius,
- J. Sarén,
- C. Scholey,
- S. Siem,
- J. Sorri,
- S. Stolze,
- J. Uusitalo
Affiliations
- F.L. Bello Garrote
- Department of Physics, University of Oslo, N-0316 Oslo, Norway; Corresponding authors.
- A. Lopez-Martens
- Laboratoire de physique des 2 infinis Irène Joliot-Curie, CNRS/IN2P3, F-91405 Orsay Cedex, France; Université Paris-Saclay, CEA, LMCE, F-91680 Bruyères-le-Châtel, France; Corresponding authors.
- A.C. Larsen
- Department of Physics, University of Oslo, N-0316 Oslo, Norway; Corresponding authors.
- I. Deloncle
- Laboratoire de physique des 2 infinis Irène Joliot-Curie, CNRS/IN2P3, F-91405 Orsay Cedex, France; CEA, DAM, DIF, F-91680 Arpajon, France
- S. Péru
- CEA, DAM, DIF, F-91680 Arpajon, France; Université Paris-Saclay, CEA, LMCE, F-91680 Bruyères-le-Châtel, France
- F. Zeiser
- Department of Physics, University of Oslo, N-0316 Oslo, Norway
- P.T. Greenlees
- University of Jyvaskyla, Department of Physics, P.O. Box 35, FI-40014 University of Jyvaskyla, Finland
- B.V. Kheswa
- Department of Physics, University of Oslo, N-0316 Oslo, Norway
- K. Auranen
- University of Jyvaskyla, Department of Physics, P.O. Box 35, FI-40014 University of Jyvaskyla, Finland
- D.L. Bleuel
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94551, USA
- D.M. Cox
- University of Jyvaskyla, Department of Physics, P.O. Box 35, FI-40014 University of Jyvaskyla, Finland
- L. Crespo Campo
- Department of Physics, University of Oslo, N-0316 Oslo, Norway
- F. Giacoppo
- Helmholtz Institute Mainz, 55099 Mainz, Germany; GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt, Germany
- A. Görgen
- Department of Physics, University of Oslo, N-0316 Oslo, Norway
- T. Grahn
- University of Jyvaskyla, Department of Physics, P.O. Box 35, FI-40014 University of Jyvaskyla, Finland
- M. Guttormsen
- Department of Physics, University of Oslo, N-0316 Oslo, Norway
- T.W. Hagen
- Department of Physics, University of Oslo, N-0316 Oslo, Norway
- L. Harkness-Brennan
- Department of Physics, University of Liverpool, Oliver Lodge Laboratory, Liverpool L69 7ZE, United Kingdom
- K. Hauschild
- Laboratoire de physique des 2 infinis Irène Joliot-Curie, CNRS/IN2P3, F-91405 Orsay Cedex, France; Université Paris-Saclay, CEA, LMCE, F-91680 Bruyères-le-Châtel, France
- G. Henning
- Universitè de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
- R.-D. Herzberg
- Department of Physics, University of Liverpool, Oliver Lodge Laboratory, Liverpool L69 7ZE, United Kingdom
- R. Julin
- University of Jyvaskyla, Department of Physics, P.O. Box 35, FI-40014 University of Jyvaskyla, Finland
- S. Juutinen
- University of Jyvaskyla, Department of Physics, P.O. Box 35, FI-40014 University of Jyvaskyla, Finland
- T.A. Laplace
- Department of Nuclear Engineering, University of California, Berkeley, CA 94720, USA
- M. Leino
- University of Jyvaskyla, Department of Physics, P.O. Box 35, FI-40014 University of Jyvaskyla, Finland
- J.E. Midtbø
- Department of Physics, University of Oslo, N-0316 Oslo, Norway
- V. Modamio
- Department of Physics, University of Oslo, N-0316 Oslo, Norway
- J. Pakarinen
- University of Jyvaskyla, Department of Physics, P.O. Box 35, FI-40014 University of Jyvaskyla, Finland
- P. Papadakis
- University of Jyvaskyla, Department of Physics, P.O. Box 35, FI-40014 University of Jyvaskyla, Finland
- J. Partanen
- University of Jyvaskyla, Department of Physics, P.O. Box 35, FI-40014 University of Jyvaskyla, Finland
- T. Renstrøm
- Department of Physics, University of Oslo, N-0316 Oslo, Norway
- K. Rezynkina
- CSNSM, IN2P3-CNRS, and Université Paris Sud, Bat. 104-108, F-91405 Orsay, France
- M. Sandzelius
- University of Jyvaskyla, Department of Physics, P.O. Box 35, FI-40014 University of Jyvaskyla, Finland
- J. Sarén
- University of Jyvaskyla, Department of Physics, P.O. Box 35, FI-40014 University of Jyvaskyla, Finland
- C. Scholey
- University of Jyvaskyla, Department of Physics, P.O. Box 35, FI-40014 University of Jyvaskyla, Finland
- S. Siem
- Department of Physics, University of Oslo, N-0316 Oslo, Norway
- J. Sorri
- University of Jyvaskyla, Department of Physics, P.O. Box 35, FI-40014 University of Jyvaskyla, Finland
- S. Stolze
- University of Jyvaskyla, Department of Physics, P.O. Box 35, FI-40014 University of Jyvaskyla, Finland
- J. Uusitalo
- University of Jyvaskyla, Department of Physics, P.O. Box 35, FI-40014 University of Jyvaskyla, Finland
- Journal volume & issue
-
Vol. 834
p. 137479
Abstract
We present the first experimental evidence of the scissors mode in the superheavy nucleus 254No produced in the 208Pb(48Ca, 2nγ))254No reaction. The spectrum of γ rays emitted by the excited 254No nuclei shows an enhanced γ-ray yield for transition energies of ≈2.5 MeV. By measuring the linear polarization properties of the emitted γ rays, we confirm that the transitions in the enhancement region are predominantly of magnetic-dipole character, characteristic for the scissors mode. To further characterize the enhanced γ-ray yield, simulations of the electromagnetic decay of 254No were performed. The observed enhancement is reproduced by including an M1 component in the γ strength function with total strength B(M1↑)=11.8(19)μN2. This is in good agreement with the integrated M1 strength from sum-rule estimates and new calculations within the quasi-particle random-phase approximation presented here. Our results provide a stringent test of phenomenological formulae for the scissors mode currently used in stellar nucleosynthesis calculations. We find that those formulae are not satisfactory, and we recommend using sum-rule estimates assuming a rigid-body moment of inertia instead for describing the scissors mode in superheavy nuclei.
