Abstract
A precision mass investigation of the neutron-rich titanium isotopes was performed at TRIUMF’s Ion Trap for Atomic and Nuclear science (TITAN). The range of the measurements covers the shell closure, and the overall uncertainties of the mass values were significantly reduced. Our results conclusively establish the existence of the weak shell effect at , narrowing down the abrupt onset of this shell closure. Our data were compared with state-of-the-art ab initio shell model calculations which, despite very successfully describing where the shell gap is strong, overpredict its strength and extent in titanium and heavier isotones. These measurements also represent the first scientific results of TITAN using the newly commissioned multiple-reflection time-of-flight mass spectrometer, substantiated by independent measurements from TITAN’s Penning trap mass spectrometer.
- Received 20 October 2017
- Revised 11 December 2017
DOI:https://doi.org/10.1103/PhysRevLett.120.062503
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