Improvements and Testing Practical Expressions for Photon Strength Functions of E1 Gamma-Transitions

Abstract

Analytical expression for the E1 photon strength functions (PSF) is modified to account for the low-energy enhancement due to nuclear structure effects (presence of low-energy state (LES)). A closed-form expression of the E1 PSF function includes response of two nuclear states: LES and giant diplole resonance (GDR). Expression for the nuclear response function on electromagnetic field is based on a model of excitation of two coupled damped states. These approach is tested for different data sets for spherical nuclei. Impact on PSF shape of coupling between LES and GDR excitations is considered.

arXiv comment4 pages, 3 figures; 1st part of the report on International Conference on Nuclear Data for Science and Technology (ND2016), (changes in table 3)

References in corpus (6)

• Further explorations of the alpha-particle optical model potential at low energies for the mass range A=45-209
• Pygmy dipole strength in 90Zr
• Photon data shed new light upon the GDR spreading width in heavy nuclei
• Pygmy dipole resonance: collective features and symmetry energy effects
• Impact of the phonon coupling on the photon strength function
• Impact of phonon coupling on the radiative nuclear reaction characteristics