Direct reactions with re-accelerated and relativistic rare isotope beams unveil new features in drip-line nuclei

The rare isotopes are bringing a wealth of new knowledge that are re-defining the global view of nuclear structure and characterizing the strong nuclear force. The properties of these isotopes are exhibiting marked deviations from the traditional nuclear structure model predictions – thereby challenging our understanding of the nuclear force. Near the drip-lines with the valence nucleons becoming weakly bound unusual nuclear forms such as the nuclear halo and Borromean three-body structures appear. These unique quantum systems portray the intricacies of the nuclear interaction – three-body force, tensor force and pairing interaction.



The presentation will show results from direct reactions with re-accelerated rare isotope beams at TRIUMF that enable spectroscopy of the near threshold unbound resonance states. The resonance properties of ⁸He [1, 2] and ¹¹Li [3-5] will be discussed. The presentation will also discuss reaction studies with relativistic in-flight beams at RIKEN-RIBF in Japan and GSI in Germany that allow to determine the nuclear radii. The presence of two-neutron halo in the N = 20 drip-line nucleus ²⁹F [6] will be discussed along with signatures of N = 14 and 16 new shell closures observed from proton radii of neutron-rich isotopes [7 – 10].

References

[1] M. Holl et al., Phys. Lett. B 822, 136710 (2021).

[2] G.Singh et al., in preparation.

[3] R. Kanungo et al., Phys. Rev. Lett. 114, 192502 (2015).

[4] J. Tanaka et al., Phys. Lett. B 774, 268 (2017).

[5] M. Singh et al., in preparation.

[6] S. Bagchi et al., Phys. Rev. Lett. 124, 222504 (2020).

[7] S. Bagchi et al., Phys. Lett. B 790, 251 (2019).

[8] S. Kaur et al., Phys. Rev. Lett. 129, 142502 (2022).

[9] A. Roy et al., in preparation.

[10] D. Prajapati et al., in preparation.