Evolution of the N=50 shell gap energy towards ${}^{78}$Ni

Abstract

Atomic masses of the neutron-rich isotopes ${}^{76-80}$Zn, ${}^{78-83}$Ga, ${}^{80-85}Ge,$^{81-87}$Asand$^{84-89}$SehavebeenmeasuredwithhighprecisionusingthePenningtrapmassspectrometerJYFLTRAPattheIGISOLfacility.Themassesof$^{82,83}$Ga,$^{83-85}$Ge,$^{84-87}$Asand$^{89}$Se were measured for the first time. These new data represent a major improvement in the knowledge of the masses in this neutron-rich region. Two-neutron separation energies provide evidence for the reduction of the N=50 shell gap energy towards germanium Z=32 and a subsequent increase at gallium (Z=31). The data are compared with a number of theoretical models. An indication of the persistent rigidity of the shell gap towards nickel (Z=28) is obtained.

4 pages, 4 figures. To be published in Physical Review Letters

References in corpus (10)

• Nuclear Ground-State Masses and Deformations
• Systematic study of deformed nuclei at the drip lines and beyond
• Global study of quadrupole correlation effects
• The Ramsey method in high-precision mass spectrometry with Penning traps: Experimental results
• High-precision mass measurements of nickel, copper, and gallium isotopes and the purported shell closure at N=40
• Theoretical Aspects of Science with Radioactive Nuclear Beams
• Precise atomic masses of neutron-rich Br and Rb nuclei close to the r-process path
• Low Energy States of ${}_{31}^{81}G{a}_{50}$ : Elements on the Doubly-Magic Nature of ${}^{78}$Ni
• Mirror displacement energies and neutron skins
• Large-Scale Self-Consistent Nuclear Mass Calculations

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