New Precision Mass Measurements of Neutron-Rich Calcium and Potassium Isotopes and Three-Nucleon Forces

Journal Article · Sun Jan 01 00:00:00 EST 2012 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.109.032506· OSTI ID:1092354

Gallant, A. T. ^[1]; Bale, J. C. ^[2]; Brunner, T. ^[1]; Chowdhury, U. ^[3]; Ettenauer, S. ^[1]; Lennarz, A. ^[4]; Robertson, D. ^[1]; Simon, V. V. ^[5]; Chaudhuri, A. ^[1]; Holt, J. D. ^[6]; Kwiatkowski, A. A. ^[1]; Mané, E. ^[1]; Menéndez, J. ^[7]; Schultz, B. E. ^[1]; Simon, M. C. ^[1]; Andreoiu, C. ^[8]; Delheij, P. ^[1]; Pearson, M. ^[1]; Savajols, H. ^[9]; Schwenk, A. ^[7] ; Dilling, J. ^[1]

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1. TRIUMF, University of British Columbia
2. TRIUMF, University of British Columbia/Simon Fraser University-Canada
3. TRIUMF, University of British Columbia/ University of Manitoba-Canada
4. TRIUMF, University of British Columbia/Westfälische Wilhelms-Universität-Germany
5. TRIUMF-Canada/Ruprecht-Karls-Universität Heidelberg/Max-Planck-Inst.-Heidelberg, Germany
6. UTK/ORNL
7. Inst. für Kernphysik, Tech. Univ. Darmstadt-Germany/ExtreMe Matter Inst., GSI-Darmstadt
8. Simon Fraser University, Canada
9. GANIL, Caen cedex, France

We present precision Penning trap mass measurements of neutron-rich calcium and potassium isotopes in the vicinity of neutron number N=32. Using the TITAN system, the mass of 51K was measured for the first time, and the precision of the 51,52Ca mass values were improved significantly. The new mass values show a dramatic increase of the binding energy compared to those reported in the atomic mass evaluation. In particular, 52Ca is more bound by 1.74 MeV, and the behavior with neutron number deviates substantially from the tabulated values. An increased binding was predicted recently based on calculations that include three-nucleon (3N) forces. We present a comparison to improved calculations, which agree remarkably with the evolution of masses with neutron number, making neutron-rich calcium isotopes an exciting region to probe 3N forces.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1092354
• Journal Information: Physical Review Letters, Vol. 109, Issue 3; ISSN 0031--9007
• Country of Publication: United States
• Language: English