Investigating a possible positive value of Kτ, and implications for the symmetry energy
Abstract
The isoscalar giant monopole resonances (ISGMR) in isotopic chains with large neutron-excess provide excellent constraints for Kτ, the asymmetry term in the nuclear incompressibility. Kτ has been extracted from the ISGMR in tin and cadmium to be - 550 +/- 100 MeV, and is critical input to the symmetry energy of nuclear matter. Recent reports on the ISGMR in 40 , 44 , 48Ca contradict the prior studies, concluding that Kτ > + 500 MeV. A simultaneous study of the ISGMR in 40 , 42 , 44 , 48Ca was thus completed at the Research Center for Nuclear Physics. The spectrograph, Grand Raiden, allowed for measurements of background-free angular distributions for inelastic scattering of 386 MeV α-particles. Multipole decomposition analyses isolated the ISGMR strength, and the energies of the compressional mode were extracted. The results and implications will be discussed.
Supported by NSF Grant No. PHY-1713857, the Liu Institute, and the College of Science at the University of Notre Dame.- Publication:
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APS Division of Nuclear Physics Meeting Abstracts
- Pub Date:
- 2019
- Bibcode:
- 2019APS..DNP.FN007H