Microscopic study of the isoscalar giant resonances in 208Pb induced by inelastic alpha scattering

摘要

The energetic beam of (spin and isospin zero) $\alpha$-particles remains avery efficient probe for the nuclear isoscalar giant resonances. In the presentwork, a microscopic folding model study of the isoscalar giant resonances in$^{208}$Pb induced by inelastic \aPb scattering at $E_{\rm lab}=240$ and 386MeV has been performed using the (complex) CDM3Y6 interaction and nucleartransition densities given by both the collective model and Random PhaseApproximation (RPA) approach. The fractions of energy weighted sum rule aroundthe main peaks of the isoscalar monopole, dipole and quadrupole giantresonances were probed in the Distorted Wave Born Approximation analysis ofinelastic \aPb scattering using the double-folded form factors given bydifferent choices of the nuclear transition densities. The energy distributionof the $E0, E1$ and $E2$ strengths given by the multipole decomposition{analyses} of the \aap data under study are compared with those predicted bythe RPA calculation.