On microscopic theory of the gamma-ray strength functions

TL;DR

This paper extends the microscopic theory of gamma-ray strength functions to non-magic nuclei using the Theory of Finite Fermi Systems, providing new insights and better agreement with experimental data compared to QRPA.

Contribution

It generalizes existing models to non-magic nuclei and compares the results with QRPA, highlighting new physics in many-body approaches.

Findings

Better agreement with experimental quadrupole moments in 208Pb

Identification of new physics in many-body approaches

Extension of theory to non-magic nuclei

Abstract

Using the Theory of Finite Fermi Systems, we obtained a non-magic nuclei generalization of the old theoretical results by J. Speth for magic nuclei dealing with the transitions between excited states and moment values of excited state. Such an extension is quite necessary for microscopic calculations of the gamma ray strength function. The comparison with the standard QRPA has shown that the modern many-body approach gives some new physics. The calculated value of the quadrupole moment of the excited state in 208Pb is agreed satisfactorily with the experiment. Some possible improvements of the theory are briefly discussed.