Simultaneous modeling of photoneutron cross sections and average neutron energies

Develop a statistical-model description that simultaneously reproduces the $(\gamma,inX)$ photoneutron cross sections and average neutron emission energies of $^{165}$Ho and $^{169}$Tm, rather than requiring different combinations of nuclear level-density and photon-strength-function models for the two observables.

Background

The authors test the EMPIRE statistical model with several phenomenological nuclear level-density (NLD) and photon-strength-function (PSF) prescriptions. The GSM+MLO2 combination gives the best description of the partial photoneutron cross sections, whereas the EGSM+SLO combination gives the best description of the average neutron energies. The inability to obtain one parameter combination that describes both observables indicates an unresolved modeling problem in the statistical treatment of photoneutron reactions for 165^{165}Ho and 169^{169}Tm.

References

We note that a simultaneous improvement in the description of the $(\gamma,\,inX)$ cross sections and average neutron energies could not be obtained by varying the optical model potentials and the NLDs and preequilibrium parameters.

— Photoneutron reactions on $^{165}$Ho and $^{169}$Tm in the giant dipole resonance region  (2609.25984 - Gheorghe et al., 22 Sep 2026) in Section 5.1, subsection “EMPIRE sensitivity test to phenomenological NLDs and PSF parametrizations”