Isospin Symmetry Breaking Disclosed in the Decay of Three-Proton Emitter 20Al
Artikel i vetenskaplig tidskrift, 2025
The previously unknown nucleus 20Al has been observed for the first time by detecting its in-flight decays. Tracking trajectories of all decay products with silicon microstrip detectors allowed for a conclusion that 20Al is unbound with respect to three-proton (3p) emission. The 3p-decay energy of the 20Al ground state has been determined to be 1.93(+0.12-0.10) MeV through a detailed study of angular correlations of its decay products, 17Ne + p + p + p. This value is significantly smaller than the predictions inferred from the isospin symmetry by using the known neutron separation energy of its mirror nucleus 20N, which indicates a possible isospin symmetry breaking in the mirror nuclei 20Al and 20N. This observed isospin symmetry breaking is supported by the calculations of the continuum embedded theoretical frameworks, describing the observed 20Al ground state as a 1p s-wave state with a spin-parity of 1-, which differs from the spin-parity (2-) of the 20N ground state. The 20Al ground state decays by sequential 1p-2p emission via the intermediate ground state of 19Mg, which is the first observed case of "daughter" 2p radioactivity following 1p decay of the parent state.
Författare
X. -D. Xu
Chinese Academy of Sciences
I. Mukha
Helmholtz-Gemeinschaft Deutscher Forschungszentren
J. G. Li
Chinese Academy of Sciences
S. M. Wang
Fudan University
National Natural Science Foundation of China (NSFC)
L. Acosta
Instituto de Nanociencia y Materiales de Aragón (INMA)
Universidad Nacional Autónoma de México
M. Bajzek
Helmholtz-Gemeinschaft Deutscher Forschungszentren
Justus-Liebig-Universität Gießen
Sveučilište u Zagrebu
E. Casarejos
Universidad de Vigo
D. Cortina-Gil
Universitat de Valencia
J. M. Espino
Universidad de Sevilla
A. Fomichev
Flerov Laboratory of Nuclear Reactions (FLNR)
H. Geissel
Helmholtz-Gemeinschaft Deutscher Forschungszentren
J. Gomez-Camacho
Universidad de Sevilla
L. V. Grigorenko
National Research Nuclear University (MEPhI)
National Research Centre "Kurchatov Institute"
Flerov Laboratory of Nuclear Reactions (FLNR)
O. Kiselev
Helmholtz-Gemeinschaft Deutscher Forschungszentren
A. A. Korsheninnikov
National Research Centre "Kurchatov Institute"
D. Kostyleva
Helmholtz-Gemeinschaft Deutscher Forschungszentren
N. Kurz
Helmholtz-Gemeinschaft Deutscher Forschungszentren
Yu. A. Litvinov
Helmholtz-Gemeinschaft Deutscher Forschungszentren
I. Martel
Universidad de Huelva
C. Nociforo
Helmholtz-Gemeinschaft Deutscher Forschungszentren
M. Pfuetzner
Helmholtz-Gemeinschaft Deutscher Forschungszentren
Uniwersytet Warszawski
C. Rodriguez-Tajes
Universidade de Santiagode Compostela
C. Scheidenberger
Justus-Liebig-Universität Gießen
Helmholtz-Gemeinschaft Deutscher Forschungszentren
K. Suemmerer
Helmholtz-Gemeinschaft Deutscher Forschungszentren
H. Weick
Helmholtz-Gemeinschaft Deutscher Forschungszentren
Justus-Liebig-Universität Gießen
P. J. Woods
University of Edinburgh
Mikhail Zhukov
Chalmers, Fysik
Physical Review Letters
0031-9007 (ISSN) 1079-7114 (eISSN)
Vol. 135 2 022502Fundament
Grundläggande vetenskaper
Ämneskategorier (SSIF 2025)
Subatomär fysik
DOI
10.1103/hkmy-yfdk
PubMed
40743202