Abstract
Mass measurements of Na31-33 and Mg31-35 using the TITAN MR-TOF-MS at TRIUMF's ISAC facility are presented, with the uncertainty of the Na33 mass reduced by over 2 orders of magnitude. The excellent performance of the MR-TOF-MS has also allowed the discovery of a millisecond isomer in Na32. The precision obtained shows that the binding energy of the normally closed N=20 neutron shell reaches a minimum for Mg32 but increases significantly for Na31, hinting at the possibility of enhanced shell strength toward the unbound O28. We compare the results with new ab initio predictions that raise intriguing questions of nuclear structure beyond the dripline.
| Original language | English |
|---|---|
| Article number | 052503 |
| Journal | Physical Review Letters |
| Volume | 134 |
| Issue number | 5 |
| DOIs | |
| State | Published - Feb 7 2025 |
Funding
This work was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC), the National Research Council of Canada (NRC), by the French IN2P3, by the German Federal Ministry for Education and Research (BMBF) under Contracts No. 05P19RGFN1 and No. 05P21RGFN1, the German Research Foundation (DFG) under Contract No. 422761894, and by Justus-Liebig-Universität Gießen and GSI under the JLU-GSI strategic Helmholtz partnership agreement. A. S. is supported by the European Union’s Horizon 2020 research and innovation program under Grant Agreement No. 800945—NUMERICS—H2020-MSCA-COFUND-2017. W. S. P. and M. B. acknowledge support from the U.S. National Science Foundation under Grant No. PHY-2011890 and No. PHY-2310059. BMBPT calculations were performed using HPC resources from GENCI-TGCC (Contract No. A0150513012). T. O. and N. S. acknowledge the support of the “Program for promoting research on the supercomputer Fugaku”, MEXT, Japan (JPMXP1020230411, hp230207, hp240213).