Bonasera, Giacomo (2019-07). Mean-Field Investigation of Strength Functions of Giant Resonances Compared with the Unexpected Experimental Characteristics. Doctoral Dissertation.
Thesis
We calculate properties of nuclear giant resonances using Hartree-Fock based Random Phase Approximation theory adopting a Skyrme-type effective interaction. Centroid energies for isoscalar and isovector giant resonances of multipolarities L = 0-3 in ^40,^48Ca, ^68Ni, ^90Zr, ^116Sn, ^144Sm and ^208Pb are obtained for 33 interactions found in the literature. We compare our theoretical results with experimental data and determine the correlation between theoretical centroid energies and each nuclear matter property related to each Skyrme interaction. We obtained strong correlations and agreement with experimental data for the isoscalar giant monopole and quadrupole resonances and the isovector giant dipole resonance (IVGDR). We determined the best range for the incompressibility coefficient (KvNvM = 210-240MeV), the effective mass (m*/m = 0.7-0.9) and the enhancement coefficient of the energy weighted sum rule of the IVGDR (? = 0.25-0.70). These constraints, valid across a wide range of masses, may be used in a fit to develop a new energy density functional with improved predictive power. We also performed a similar analysis for two mass regions: A = 90-100 and A = 44-68. Interest recently arose in these regions when we found significant disagreements between experiment and theory for certain isotopes. Therefore, we extended our investigation to determine if other interactions agreed with the experimental results. However, we found that none of the interactions considered reproduced the unexpected experimental characteristics.
