Absence of a shell closure in $^{140}$Sn

Francesca Bonaiti; Bingcheng He; Gaute Hagen; Thomas Papenbrock

Absence of a shell closure in $^{140}$Sn

Nuclear Theory 2026-07-10 v1 Nuclear Experiment

Authors: Francesca Bonaiti , Bingcheng He , Gaute Hagen , Thomas Papenbrock

Abstract

There are conflicting theoretical results about the presence of a shell closure in the neutron-rich nucleus $^{140}$ Sn. We address this controversy by performing ab initio computations, using a nuclear interaction from chiral effective field theory that accurately reproduced and predicted low-lying states in doubly magic nuclei. We verify that this interaction accurately reproduces low-lying states in $^{133}$ Sn. We assume that $^{140}$ Sn exhibits a closed $7/2^-$ neutron subshell beyond $^{132}$ Sn and compute its first excited $2^+$ state. The resulting energy is small and this contradicts the assumption.

Keywords

shell closure tin isotopes ab initio calculations chiral effective field theory neutron-rich nuclei excited states

Cite

@article{arxiv.2607.09897,
  title  = {Absence of a shell closure in $^{140}$Sn},
  author = {Francesca Bonaiti and Bingcheng He and Gaute Hagen and Thomas Papenbrock},
  journal= {arXiv preprint arXiv:2607.09897},
  year   = {2026}
}

Comments

9 pages, 3 figures