The unbound isotopes He-9,He-10
Journal article, 2010
The unbound nuclei He-9 and He-10 have been produced in proton-knockout reactions from a 280 MeV/u Li-11 beam impinging on a liquid hydrogen target at the ALADIN-LAND setup at GSI. Information on their nuclear structure has been obtained from the relative-energy spectra, He-8 + n and He-8 + 2n, employing reaction models incorporating the structure of Li-11. The (8H)e + n relative-energy spectrum is dominated by a strong peak-like structure at low energy, which may be interpreted within the effective-range approximation as the result of an s-wave interaction with a neutron scattering length of -3.17(66) fm. This spectrum also shows evidence for resonance states at 1.33(8) MeV and at 2.4 MeV above the He-8 + n threshold. It is argued that the s-state might not be the He-9 ground state. For He-8 + n + n, the analysis of the relative-energy spectrum gives two alternative possibilities for an interpretation: either a narrow resonance at 1.42(10) MeV (Gamma = 1.11(76) MeV) superimposed on a correlated background, or two overlapping resonances, a ground state at 1.54(11) MeV (Gamma = 1.91(41) MeV) together with an excited state at 3.99(26) MeV (Gamma = 1.64(89) MeV). The two possible interpretations are discussed. (C) 2010 Elsevier B.V. All rights reserved.
borromean-nuclei
li-11
2p)
relative energy spectra
n2p)
deduced resonance state parameters
fragmentation
ground-state
model
E=280 MeV/nucleon
spectroscopy
halo
he-10
measured fragment spectra
(fragment) (neutron)-coin
NUCLEAR REACTIONS H-1(Li-11
neutron spectra
nuclei
nuclear reactions
exotic nuclei
(Li-11
Author
Håkan T Johansson
Chalmers, Applied Physics, Subatomic Physics
Yuliya Aksyutina
Chalmers, Applied Physics, Subatomic Physics
T. Aumann
K. Boretzky
M. J. G. Borge
A. Chatillon
L. V. Chulkov
D. Cortina-Gil
U. D. Pramanik
H. Emling
Christian Forssen
Chalmers, Applied Physics, Subatomic Physics
H. O. U. Fynbo
H. Geissel
G. Ickert
Björn Jonson
Chalmers, Applied Physics, Subatomic Physics
R. Kulessa
C. Langer
Mattias Lantz
Chalmers, Applied Physics, Subatomic Physics
T. LeBleis
K. Mahata
Mikael Meister
Chalmers, Applied Physics, Subatomic Physics
G. Munzenberg
Thomas Nilsson
Chalmers, Applied Physics, Subatomic Physics
Göran Hugo Nyman
Chalmers, Applied Physics, Subatomic Physics
R. Palit
S. Paschalis
W. Prokopowicz
R. Reifarth
A. Richter
K. Riisager
G. Schrieder
H. Simon
K. Summerer
O. Tengblad
H. Weick
Mikhail Zhukov
Chalmers, Applied Physics, Subatomic Physics
Nuclear Physics A
0375-9474 (ISSN)
Vol. 842 1-4 15-32Subject Categories
Subatomic Physics
Physical Sciences
Roots
Basic sciences
DOI
10.1016/j.nuclphysa.2010.04.006