Precision Mass Measurements of Neutron-Rich Scandium Isotopes Refine the Evolution of N=32 and N=34 Shell Closures.

Autor:	Leistenschneider E; Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA.; National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA., Dunling E; TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada.; Department of Physics, University of York, York YO10 5DD, United Kingdom., Bollen G; Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA.; National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA.; Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA., Brown BA; Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA.; National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA.; Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA., Dilling J; TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada.; Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada., Hamaker A; Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA.; National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA.; Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA., Holt JD; TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada.; Department of Physics, McGill University, 3600 Rue University, Montréal, Quebec H3A 2T8, Canada., Jacobs A; TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada.; Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada., Kwiatkowski AA; TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada.; Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8P 5C2, Canada., Miyagi T; TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada., Porter WS; TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada.; Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada., Puentes D; Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA.; National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA.; Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA., Redshaw M; National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA.; Department of Physics, Central Michigan University, Mount Pleasant, Michigan 48859, USA., Reiter MP; TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada.; II. Physikalisches Institut, Justus-Liebig-Universität, 35392 Gießen, Germany.; School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3FD, United Kingdom., Ringle R; Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA.; National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA., Sandler R; Department of Physics, Central Michigan University, Mount Pleasant, Michigan 48859, USA., Sumithrarachchi CS; Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA.; National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA., Valverde AA; Department of Physics & Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada., Yandow IT; Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA.; National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA.; Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA.
Jazyk:	angličtina
Zdroj:	Physical review letters [Phys Rev Lett] 2021 Jan 29; Vol. 126 (4), pp. 042501.
DOI:	10.1103/PhysRevLett.126.042501
Abstrakt:	We report high-precision mass measurements of ^{50-55}Sc isotopes performed at the LEBIT facility at NSCL and at the TITAN facility at TRIUMF. Our results provide a substantial reduction of their uncertainties and indicate significant deviations, up to 0.7 MeV, from the previously recommended mass values for ^{53-55}Sc. The results of this work provide an important update to the description of emerging closed-shell phenomena at neutron numbers N=32 and N=34 above proton-magic Z=20. In particular, they finally enable a complete and precise characterization of the trends in ground state binding energies along the N=32 isotone, confirming that the empirical neutron shell gap energies peak at the doubly magic ^{52}Ca. Moreover, our data, combined with other recent measurements, do not support the existence of a closed neutron shell in ^{55}Sc at N=34. The results were compared to predictions from both ab initio and phenomenological nuclear theories, which all had success describing N=32 neutron shell gap energies but were highly disparate in the description of the N=34 isotone.
Databáze:	MEDLINE
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