Speaker
Description
Neutron-rich oxygen isotopes provide a unique probe to test state-of-the-art shell-model interactions such as SFO-tls [1] and YSOX [2]. In particular, 19O and 20O isotopes can be further employed to constrain shell evolution near the drip-lines, a crucial step towards a universal interaction. In this regard, single-nucleon transfer reactions are suitable tools to study the single-particle nature of the populated states, enabling the extraction of valuable model inputs, such as spectroscopic factors and excitation energies.
To this end, neutron pick-up reactions 20O(p, d) and 20O(d, t) were performed at a beam energy of 35 AMeV at GANIL. The experimental setup featured the active target ACTAR TPC [3, 4], serving both as a thick gaseous target and as a detection medium for particle tracking, resulting in an overall enhancement of the experimental resolution compared to a conventional thick-target experiment. Additional silicon detectors surrounding the active volume measured the residual energy of the light reaction products, enabling unambiguous particle identification (PID) [5].
This talk will present preliminary results on the low-lying spectroscopy of 19O, along with a comparison to theoretical shell-model calculations and an analysis of the N = 8 shell gap behaviour. Additionally, the inelastic scattering 20O(d, d′) data have been analyzed, and early results on the inelastic excitations will also be discussed.
References
[1] T. Suzuki et al., Phys. Rev. C 78, 061301 (2008).
[2] C. Yuan et al., Phys. Rev. C 85, 064324 (2012).
[3] B. Mauss et al., Nucl. Instrum. Methods Phys. Res. A 940, 498–504 (2019).
[4] T. Roger et al., Nucl. Instrum. Methods Phys. Res. A 895, 126–134 (2018).
[5] J. Lois-Fuentes, “Complete spectroscopy of 16C and 20O with solid and active targets using transfer reactions”, Ph.D. thesis (Universidade de Santiago de Compostela, Spain, 2023).
