Predicted size of neutron and matter distributions in exotic neon isotopes (red lines) are shown along with the matter distribution for "normal" nuclei without a halo structure (black line). Our systematic calculations predict a sudden significant increase in size for 31Ne, but no such increase for 29Ne.
- Recent measurements of Neon isotopes with large neutron excesses suggested that both 29Ne and 31Ne have an significantly extended size – a “halo”
- Other studies questioned a halo in 29Ne, and the underlying causes of possible halos are uncertain
- To address this dispute, we made the first self-consistent microscopic systematic theoretical study of neutron-rich neon isotopes to clarify the existence and cause of possible halos
- A relativistic mean field model with continuum contributions & BCS pairing was used in this study
- Our calculations predict a sudden increase in matter radius at 31Ne; the change from 30Ne to 31Ne is 7 - 8 times larger than that from 29Ne to 30Ne. We also predict a significantly lower separation energy for 31Ne than its neighbors
- The large radius and lower binding suggest that 31Ne is a halo nucleus. However, no such features are shown for 29Ne in our systematic calculations
- The cause of the 31Ne halo is a large occupancy of a 2p3/2 orbital with a positive energy and a dilute density distribution
Shisheng Zhang, Michael Smith, Zhong-Shu Kang, Jie Zhao, Phys. Rev. Lett. B 370 (2014) 30
For more information contact Michael Smith (smithms@ornl.gov)