English

Quasi-elastic scattering for the nuclear ground state structure: An intriguing case of $^{30}$Si

Nuclear Experiment 2026-02-09 v1 Nuclear Theory

Abstract

Quasi-elastic (QEL) scattering measurements have been performed using the 28,30^{28, 30}Si projectiles off the 90^{90}Zr target at energies around the Coulomb barrier. Coupled-channels (CC) calculations were carried out in a large parameter space of quadrupole and hexadecapole deformations for the N=Z, 28^{28}Si and N=Z+2, 30^{30}Si nuclei. 28^{28}Si at the N=Z line is observed to be uniquely oblate shaped in its ground state. In contrast, for 30^{30}Si with just two additional neutrons -- oblate, prolate, and spherical CC descriptions are equally compatible with the measurements. To further investigate the nuclear structure evolution with varying neutron number, shell-model calculations were performed. These calculations reveal a sudden change in the nuclear structure aspects at 30^{30}Si in going from 28^{28}Si to 30^{30}Si. Combined reaction and structure analyses consistently indicate that 30^{30}Si does not possess a well-defined intrinsic shape, and it is a potential candidate for ``shape fluctuations" in its ground state.

Keywords

Cite

@article{arxiv.2602.06580,
  title  = {Quasi-elastic scattering for the nuclear ground state structure: An intriguing case of $^{30}$Si},
  author = {Y. K. Gupta and B. Maheshwari and G. K. Prajapati and A. K. Jain and K. Hagino and B. N. Joshi and A. Pal and N. Sirswal and Pawan Singh and S. Dubey and V. V. Desai and V. Ranga and V. B. Katariya and D. Patel and H. Vyas and S. Panwar and B. V. John and I. Mazumdar and B. K. Nayak and U. Garg},
  journal= {arXiv preprint arXiv:2602.06580},
  year   = {2026}
}