English

Proton inelastic scattering reveals deformation in $^8$He

Nuclear Experiment 2021-10-19 v1 Nuclear Theory

Abstract

A measurement of proton inelastic scattering of 8^8He at 8.25A8.25A~MeV at TRIUMF shows a resonance at 3.54(6)~MeV with a width of 0.89(11)~MeV. The energy of the state is in good agreement with coupled cluster and no-core shell model with continuum calculations, with the latter successfully describing the measured resonance width as well. Its differential cross section analyzed with phenomenological collective excitation form factor and microscopic coupled reaction channels framework consistently reveals a large deformation parameter β2\beta_2 = 0.40(3), consistent with no-core shell model predictions of a large neutron deformation. This deformed double-closed shell at the neutron drip-line opens a new paradigm.

Keywords

Cite

@article{arxiv.2110.01592,
  title  = {Proton inelastic scattering reveals deformation in $^8$He},
  author = {M. Holl and R. Kanungo and Z. H. Sun and G. Hagen and J. A. Lay and A. M. Moro and P. Navrátil and T. Papenbrock and M. Alcorta and D. Connolly and B. Davids and A. Diaz Varela and M. Gennari and G. Hackman and J. Henderson and S. Ishimoto and A. I. Kilic and R. Krücken and A. Lennarz and J. Liang and J. Measures and W. Mittig and O. Paetkau and A. Psaltis and S. Quaglioni and J. S. Randhawa and J. Smallcombe and I. J. Thompson and M. Vorabbi and M. Williams},
  journal= {arXiv preprint arXiv:2110.01592},
  year   = {2021}
}

Comments

9 pages, 5 figures. Accepted for publication in Physics Letters B