Damping of the isovector giant dipole resonance in 40,48Ca

Damping Rates of Hot Giant Dipole Resonances

The damping rate of hot giant dipole resonances (GDR) is investigated. Besides Landau damping we consider collisions and density fluctuations as contributions to the damping of GDR. Within the nonequilibrium Green’s function method we derive a non-Markovian kinetic equation. The linearization of the latter one leads to complex dispersion relations. The complex solution provides the centroid ene...

The Giant Nuclear Dipole Resonance

above the ground state, where a rough calculation indicates S'6 =80 Mev, a result which is in agreement with the experimentally observed position of the giant resonance. We find the p-ray width of this level to be proportional to A&, and use the width to obtain the cross sections for absorption and scattering of y rays in this region. Throughout we have neglected certain effects of the (r 'r, &...

Population of Isomers in Decay of the Giant Dipole Resonance

The value of an isomeric ratio (IR) in N=81 isotones (137Ba, 139Ce, 141Nd and 143Sm) is studied by means of the (γ, n) reaction. This quantity measures a probability to populate the isomeric state in respect to the ground state population. In (γ, n) reactions, the giant dipole resonance (GDR) is excited and after its decay by a neutron emission, the nucleus has an excitation energy of a few MeV...

EVIDENCE FOR THE ISOSCALAR GIANT DIPOLE RESONANCE IN 208Pb

Excitation-energy dependence of the giant dipole resonance width.

High-energy y rays have been measured in coincidence with heavy fragments in deeply inelastic reactions of ' 6xe+ Ti at 18.5 MeV/nucleon. The giant dipole resonance (GDR) strength function is deduced from an analysis of the photon spectra within the statistical model. The GDR width I is studied as a function of the fragment excitation energy E*. A saturation at about I =10 MeV is observed for E...