A new approach to nuclear level densities: The QRPA plus boson expansion

Abstract

Nuclear level densities play a key role in many nuclear applications. To go beyond the usual particle-independent approximation, a conceptually new approach based on the boson expansion of QRPA excitations is proposed. The calculated nuclear level densities are shown to follow an energy dependence close to a constant-temperature formula at energies above a few MeV, but present a rather narrow spin distribution. They are shown to provide a quite remarkable agreement with s-wave resonance spacings and Oslo data, at least for the 48 even-even nuclei considered in the present study.

Keywords

• Nuclear level density
• QRPA boson
• (n,γ) cross section