Speaker
Description
While maintaining the standard definition of the photon force function, many models have been developed to compensate for the lack of data for experimentally inaccessible nuclei.
In this context, the added value of microscopic approaches and the progressive reduction of phenomenological ingredients introduced in their post-processing will be presented.
As a key ingredient of microscopic strength function models, the quasi-particle random phase approximation (QRPA) approach, in particular using the effective Gogny interaction [1],
can be applied to spherical as well as deformed nuclei, to light (such as oxygen) as well as to superheavy elements.
Despite the computationally intensive effort required, large-scale calculations of the dipole strength functions have been performed with limited phenomenological ingredients [2,3,4]. The resulting photon strength functions have been shown to reproduce all experimental data with a high level of accuracy [5].
Although many other observables can be obtained within the standard QRPA,
the prediction of the half-lives of isomeric states in $N=100$ isotones [6] has been shown to require the calculation of the Coriolis coupling, i.e. transition probabilities between QRPA states.
Such intra- or inter-band transitions can be extended to electromagnetic operators to enrich the microscopic description of the dipole strength function
with a special attention to describe as well the upbend observed in the Oslo data [5].
Today, this new development allows us to systematically estimate the de-excitation photon strength function of prime relevance in the calculation of radiative capture cross sections. The de-excitation dipole strength function has been compared to the photo-absorption strength function, revealing possible deviations from the Brink hypothesis [7].
[1] S. Péru and Martini, Eur. Phys. J. A 50: 88 (2014);
[2] M. Martini S. Péru, S. Hilaire, S. Goriely, F. Lechaftois, Phys.Rev. C 94, 014304 (2016);
[3] S. Goriely, S. Hilaire, S. Péru, {\it et al.}, Phys.Rev. C 94, 044306 (2016);
[4] S. Goriely, S. Hilaire, S. Péru, and K. Sieja, Phys.Rev. C 98, 014327 (2018);
[5] S. Goriely {\it et al.}, The European Physical Journal A 55, 172 (2019);
[6] L. Gaudefroy, S. Péru {\it et al}, Phys.Rev. C 97, 064317 (2018);
[7] S. Goriely, S. Péru and S. Hilaire, Phys. Lett. B 868 (2025) 139677.
| Contribution category | Theory |
|---|---|
| Presenter status | Faculty/Staff |