8 research outputs found
Particle-hole state densities with non-equidistant single-particle levels
The correct use of energy-dependent single-particle level (s.p.l.) densities
within particle-hole state densities based on the equidistant spacing model
(ESM) is analysed. First, an analytical expression is obtained following the
convolution of energy-dependent excited-particle and hole densities. Next, a
comparison is made with results of the ESM formula using average s.p.l.
densities for the excited particles and holes, respectively. The Fermi-gas
model (FGM) s.p.l. densities calculated at the corresponding average excitation
energies are used in both cases. The analysis concerns also the density of
particle-hole bound states. The pairing correlations are taken into account
while the comparison of various effects includes the exact correction for the
Pauli exclusion principle. Quantum-mechanical s.p.l. densities and the
continuum effect can also match a corresponding FGM formula, suitable for use
within the average energy-dependent partial state density in multistep reaction
models.Comment: 29 pages, ReVTeX, 11 postscript figures, submitted to Phys.Rev.