Identification of Prompt Proton Emission in N = Z - 1 ⁶¹Ga: Isospin Symmetry at the Limit of Nuclear Binding

Summary, in English

Excited states in the proton drip line nucleus ⁶¹Ga were populated via the fusion-evaporation reaction ²⁴Mg(⁴⁰Ca,p2n)⁶¹Ga. The experimental setup at Argonne National Laboratory comprised a novel combination of the Gammasphere array with two CD-shaped double-sided Si-strip detectors inside the Microball CsI(Tl) charged-particle detection array, as well as the Neutron-Shell liquid scintillators and the Fragment Mass Analyzer. Owing to the setup’s unprecedented in-beam proton spectroscopy and tracking capabilities, a coincidence between a 957.6(5)-keV γ ray and a 1.876(24)-MeV proton line was observed, which identifies the quasibound proton πg_9/2 single-particle state in ⁶¹Ga at E_x = 2150(34) keV. This probes isospin symmetry at the limit of nuclear binding by providing a unique challenge for the shell-model
interpretation of mirror nuclei beyond doubly magic ⁵⁶Ni.

• Author: Y. Hrabar; P. Golubev; D. Rudolph; L. G. Sarmiento; C. Müller-Gatermann; W. Reviol; D. Seweryniak; J. Wu; H. M. Albers; J. T. Anderson; M. A. Bentley; B. G. Carlsson; M. P. Carpenter; C. J. Chiara; P. A. Copp; D. M. Cox; J. Ekman; C. Fahlander; U. Forsberg; T. Huang; A. Idini; H. Jayatissa; T. Lauritsen; X. Pereira-Lopez; S. Stolze; S. Uthayakumaar; G. L. Wilson
• Department/s: Particle and nuclear physics; Mathematical Physics; Nuclear physics
• Publishing year: 2025-11-25
• Language: English
• Publication/Series: Physical Review Letters
• Volume: 135
• Issue: 22
• Full text: - 351 kB; Download statistics
• Links: http://dx.doi.org/10.1103/kwm2-9bmd
• Document type: Journal article
• Publisher: American Physical Society
• Topic: Subatomic Physics
• Keywords: nuclear structure and decays; proton radioactivity; nuclear data analysis and compilation; radiation detectors; isospin symmetry; 59 <= A <= 89
• Status: Published
• Project: Decay Modes of Exotic Nuclei; Nuclear Structure at the Limits: Isotope-selective Spectroscopy
• ISBN/ISSN/Other: ISSN: 1079-7114