原子核集体激发的费米液体模型研究 - kitpc.PPT

Nuclear Collective Excitation in a Femi-Liquid Model Bao-Xi SUN Beijing University of Technology 2012.06.15 KITPC, Beijing Content Fermi-liquid Model based on Landau Theory. Relation between isoscalar giant resonance and isovector giant resonance Collective excitation in nuclear matter Collective excitation in finite nuclei Conclusion Fermi-liquid Model based on Landau Theory Xiao-Gang Wen, Quantum field theory of many-body systems, Oxford University Press, Oxford, 2004. Boltzmann Equation of quasi-nucleons Boltzmann equation of nucleons where Density of quasi-nucleons The quasi-nucleon density near the Fermi-surface: with Vibrations of Fermi surface Linearized liquid equation of motion in the momentum space with and Potential between nucleons in the linear Walecka model Fermi liquid function Fermi liquid function with and Fermi energy and Fermi velocity C. J. Horowitz and B. D. Serot, Nucl. Phys. A368 (1981) 503 The quasi-nucleon density can be expanded in spherical harmonics: Liquid equation of motion in spherical harmonics The stability of the Fermi liquid requires the diagonal matrix elements of M must be positive definite, and we can write M as M =W WT. Letting Eigen-energy equation for the nuclear collective excitation with the Hamiltonian and Eigenvalues of the Hamiltonian Since the nucleon near Fermi-surface is easier to be excited, in the following calculation, we set the value of nucleon momentum Collective excitation energy El .vs. effective mass M*N .  L=0,Dash;L=1,Solid;L=2,Dot. Collective excitation Relation between isoscalar and isovector giant resonances The nuclear isovector giant resonances correspond to the nuclear collective excitation that the collective excitation of protons is creating with the energy ES(l), while the collective excitation of neutrons is annihilating with the energy ES(l), and vice versa. Relation between isoscalar and isovector giant resonances The energy of the nuclear isovector gi