Resonant states in H 7: Experimental studies of the H 2 (He 8, He 3) reaction
Journal article, 2021
The extremely neutron-rich system H7 was studied in the direct H2(He8,He3)H7 transfer reaction with a 26 AMeV secondary He8 beam [Bezbakh et al., Phys. Rev. Lett. 124, 022502 (2020)PRLTAO0031-900710.1103/PhysRevLett.124.022502]. The missing mass spectrum and center-of-mass angular distributions of H7, as well as the momentum distribution of the H3 fragment in the H7 frame, were constructed. In addition, we carried out another experiment with the same beam but a modified setup, which was cross-checked by the study of the H2(Be10,He3)Li9 reaction. A solid experimental evidence is provided that two resonant states of H7 are located in its spectrum at 2.2(5) and 5.5(3)MeV relative to the H3+4n decay threshold. Also, there are indications that the resonant states at 7.5(3) and 11.0(3)MeV are present in the measured H7 spectrum. Based on the energy and angular distributions, obtained for the studied H2(He8,He3)H7 reaction, the weakly populated 2.2(5)-MeV peak is ascribed to the H7 ground state. It is highly plausible that the firmly ascertained 5.5(3)-MeV state is the 5/2+ member of the H7 excitation 5/2+-3/2+ doublet, built on the 2+ configuration of valence neutrons. The supposed 7.5-MeV state can be another member of this doublet, which could not be resolved in Bezbakh et al. [Phys. Rev. Lett. 124, 022502 (2020)PRLTAO0031-900710.1103/PhysRevLett.124.022502]. Consequently, the two doublet members appeared in the spectrum of H7 in the work mentioned above as a single broad 6.5-MeV peak.
Author
I. A. Muzalevskii
Joint Institute for Nuclear Research (JINR)
Slezska univerzita v Opave
A.A. Bezbakh
Slezska univerzita v Opave
Joint Institute for Nuclear Research (JINR)
E.Y. Nikolskii
National Research Centre "Kurchatov Institute"
Joint Institute for Nuclear Research (JINR)
V. Chudoba
Slezska univerzita v Opave
Joint Institute for Nuclear Research (JINR)
S. A. Krupko
Joint Institute for Nuclear Research (JINR)
S. G. Belogurov
National Research Nuclear University
Joint Institute for Nuclear Research (JINR)
D. Biare
Joint Institute for Nuclear Research (JINR)
A. S. Fomichev
Dubna International University
Joint Institute for Nuclear Research (JINR)
E. M. Gazeeva
Joint Institute for Nuclear Research (JINR)
A. V. Gorshkov
Joint Institute for Nuclear Research (JINR)
L Grigorenko
National Research Nuclear University
Joint Institute for Nuclear Research (JINR)
National Research Centre "Kurchatov Institute"
G. Kaminski
University of Warsaw
Joint Institute for Nuclear Research (JINR)
O. Kiselev
Helmholtz
D. Kostyleva
Helmholtz
Justus Liebig University Giessen
M. Yu Kozlov
Joint Institute for Nuclear Research (JINR)
B. Mauyey
L.N. Gumilyov Eurasian National University
Joint Institute for Nuclear Research (JINR)
I. G. Mukha
Helmholtz
Y. L. Parfenova
Joint Institute for Nuclear Research (JINR)
W. Piatek
Joint Institute for Nuclear Research (JINR)
University of Warsaw
A. M. Quynh
Joint Institute for Nuclear Research (JINR)
Institute for Nuclear Research Vietnam
V. N. Schetinin
Joint Institute for Nuclear Research (JINR)
A. Serikov
Joint Institute for Nuclear Research (JINR)
S. I. Sidorchuk
Joint Institute for Nuclear Research (JINR)
P.G. Sharov
Joint Institute for Nuclear Research (JINR)
Slezska univerzita v Opave
N. B. Shulgina
National Research Centre "Kurchatov Institute"
Joint Institute for Nuclear Research (JINR)
R. S. Slepnev
Joint Institute for Nuclear Research (JINR)
S. V. Stepantsov
Joint Institute for Nuclear Research (JINR)
A. Swiercz
Joint Institute for Nuclear Research (JINR)
AGH University of Science and Technology
P. Szymkiewicz
Joint Institute for Nuclear Research (JINR)
AGH University of Science and Technology
G. M. Ter-Akopian
Joint Institute for Nuclear Research (JINR)
Dubna International University
R. Wolski
Joint Institute for Nuclear Research (JINR)
Polish Academy of Sciences
B. Zalewski
Joint Institute for Nuclear Research (JINR)
University of Warsaw
Mikhail Zhukov
Chalmers, Physics
Physical Review C
24699985 (ISSN) 24699993 (eISSN)
Vol. 103 4 044313Subject Categories
Accelerator Physics and Instrumentation
Subatomic Physics
Atom and Molecular Physics and Optics
DOI
10.1103/PhysRevC.103.044313