Spectroscopy of 26F to Probe Proton-Neutron Forces Close to the Drip Line

Journal Article · Tue Jan 01 04:00:00 EST 2013 · Physical Review Letters

OSTI ID:1092357

Hagen, Gaute ^[1]; Sorlin, O. ^[2]; Borcea, C. ^[3]; Brown, B. A. ^[4]; Grevy, S. ^[2]; Grinyer, G. F. ^[4]; Hjorth-Jensen, Morten ^[1]; Jansen, G. R. ^[5]; Negoita, F. ^[3]; Thomas, J. -C. ^[6]

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1. ORNL
2. Grand Accelerateur National d'Ions Lourds (GANIL)
3. IFIN, Bucharest-Magurele, Romania
4. Michigan State University, East Lansing
5. UTK/ORNL
6. CEN Bordeaux-Gradignan/CNRS, France

A long-lived J 4 1 isomer, T1=2 2:2 1 ms, has been discovered at 643.4(1) keV in the weakly bound 26 9 F nucleus. It was populated at Grand Acce le rateur National d Ions Lourds in the fragmentation of a 36S beam. It decays by an internal transition to the J 1 1 ground state [82(14)%], by decay to 26Ne, or -delayed neutron emission to 25Ne. From the -decay studies of the J 1 1 and J 4 1 states, new excited states have been discovered in 25;26Ne. Gathering the measured binding energies of the J 1 1 4 1 multiplet in 26 9 F, we find that the proton-neutron 0d5=20d3=2 effective force used in shell-model calculations should be reduced to properly account for the weak binding of 26 9 F. Microscopic coupled cluster theory calculations using interactions derived from chiral effective field theory are in very good agreement with the energy of the low-lying 1 1 , 2 1 , 4 1 states in 26F. Including three-body forces and coupling to the continuum effects improve the agreement between experiment and theory as compared to the use of two-body forces only.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1092357
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 8 Vol. 110
• Country of Publication: United States
• Language: English