Giant resonances in40Ca and48Ca

Abstract

We present results of fully self-consistent Hartree-Fock based random phase approximation calculations of the strength functions S(E) and centroid energies E CEN of isoscalar (T = 0) and isovector (T = 1) giant resonances of multipolarities L = 0 -3 in 40 Ca and 48 Ca, using a wide range of commonly employed 18 Skyrme type nucleonnucleon effective interactions. We determined the sensitivities of E CEN and of the isotopic differences E CEN ( 48 Ca) -E CEN ( 40 Ca) to physical quantities, such as nuclear matter incompressibility coefficient, symmetry energy density and effective mass, associated with the Skyrme interactions and compare the results with the available experimental data.

Isoscalar dipole transition as a probe for asymmetric clustering

“…The observed electric monopole (E0) and isoscalar (IS) monopole strength distributions of light nuclei [1][2][3][4][5][6][7][8][9][10][11][12][13][14] show that a considerable amount of the strength fractions appears at relatively small excitation energy as sharp resonances. It was known that many of those resonances are associated with the α cluster states such as the Hoyle state of 12 C [15][16][17][18][19][20][21][22][23][24], the α + 12 C cluster states in 16 O [25,26], the α + 16 O cluster states in 20 Ne [27], and the α + α + t cluster state in 11 B [28][29][30].…”

“…As an alternative, one may consider the IS dipole transition, because it populates 1 − states and has an operator form that is similar to the IS monopole transition. Furthermore, its strength distributions measured for light nuclei [4][5][6]10,11,13,35,36] show the existence of the sharp resonances with enhanced strengths at relatively small excitation energies well below the giant resonance. In a recent experimental study [35], the observed low-lying resonances in 32 S are conjectured to be the α + 28 Si cluster states, because of their enhanced IS dipole transition strength from the ground state.…”

Isoscalar and Isovector Giant Monopole Resonances from a Continuum Hartree-Fock Method

“…However, isospin, as an approximately good quantum number in nuclei, is a useful classification of nuclear excitation modes, and reaction mechanisms often begin an oscillation in just one isospin mode. Giant Monopole resonances date experimentally to the late 1970s [4,5], and have been a topic of ongoing theoretical study [6][7][8][9], not least for their link to nuclear matter properties [10,12] In applying exact boundary conditions to the case of giant monopole resonances within the timedependent Hartree Fock framework, we use a zero-range version of the Skyrme interaction, as commonly used in exploratory work [7]. We take the parameters t 0 = −1090.0 MeV fm 3 and t 3 = 17288.0 MeV fm 6 [7] for all calculations presented.…”

IsoscalarE0,E1,E2, andE3strength inMoYoungblood1, Lui2, Krishichayan3 et al. 2015Phys. Rev. CSelf Cite24020View full textAdd to dashboardCite

“…The energy moments of the calculated strength functions were obtained using small smearing widths (0.1 MeV) to insure accuracy and they are given in Tables II-V Table IV, and 100 Mo (53±7%) are somewhat lower than the 63.85% and 61.80% obtained with the KDE0v1 interaction. The energies of the HEOR and the GQR are sensitive to the effective mass [26], and a larger effective mass would result in a lower energy for both these excitations.…”