Speaker
Description
The history of Coulomb-excitation measurements with the new-generation
European γ-ray spectrometer AGATA dates back to the very first physics experiment with this array, which took place in April 2010 and aimed at investigation of a highly-deformed structure in 42Ca [1]. The shape parameters obtained from this study confirm that the excited structure in 42Ca possesses a strikingly large elongation, similar to that established for superdeformed bands in this mass region, and a slightly non-axial character. In contrast, those for the ground state are consistent with large fluctuations about a spherical shape.
During the AGATA campaign at GANIL (2014-2021) Coulomb-excitation data were collected as a by-product of experiments performed at near-barrier beam energies. Notably, the analysis of slightly ”unsafe” Coulomb-excitation data on 106Cd, collected during an experiment aiming at lifetime measurements in 106,108Sn [2], provides information on the collectivity of the presumably oblate structure built on the 0+3 state, as well as on the role of octupole correlations in this nucleus [3, 4].
Coulomb-excitation experiments to study nuclear shapes constitute one
of the pillars of the on-going AGATA campaign at LNL (2022-2028). Their
main focus is on multiparticle-multihole excitations across the Z = 50 shell gap in Cd, Pd, and Te nuclei, although the structure of nuclei as light as 8Li and as heavy as 232Th has also been probed using this method. Another area of interest has been the region of light A ≈ 70 nuclei known for prolate-oblate shape coexistence.
I will discuss the highlights from Coulomb-excitation studies with AGATA, as well as preliminary results of selected experiments from the current campaign.
References
[1] K. Hady´nska-Kl¸ek et al., Phys. Rev. Lett. 117, 062501 (2016).
[2] M. Siciliano et al., Phys. Lett. B 806, 135474 (2020).
[3] D. Kalaydjieva, PhD thesis, Universit´e Paris-Saclay, 2023.
[4] D. Kalaydjieva, submitted to Eur. Phys. J. A (2026).