Properties of the 7He ground state from 8He neutron knockout
Journal article, 2009
The unbound nucleus 7He, produced in neutron-knockout reactions with a 240 MeV/u 8He beam in a liquid-hydrogen target, has been studied in an experiment at the ALADIN-LAND setup at GSI. From an R-matrix analysis the resonance parameters for 7He as well as the spectroscopic factor for the 6He(0+) + n configuration in its ground-state have been obtained. The spectroscopic factor is 0.61 confirming that 7He is not a pure single-particle state. An analysis of 5He data from neutron-knockout reactions of 6He in a carbon target reveals the presence of an s-wave component at low energies in the α+n relative energy spectrum.
A possible low-lying exited state in 7He observed in neutron knockout data from 8He in a carbon target and tentatively interpreted as a Iπ=1/2− state, could not be observed in the present experiment. Possible explanations of the shape difference between the 7He resonance obtained in the two knockout reactions are discussed in terms of target-dependence or different reaction mechanisms at relativistic energies.
Author
Yuliya Aksyutina
Chalmers, Applied Physics, Subatomic Physics
Håkan T Johansson
Chalmers, Applied Physics, Subatomic Physics
T. Aumann
K. Boretzky
M. J. G. Borge
A. Chatillon
L.V. Chulkov
D. Cortina-Gil
U. Datta 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
Anton Lindahl
University of Gothenburg
K. Mahata
Mikael Meister
Chalmers, Applied Physics, Subatomic Physics
G. Münzenberg
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. Sümmerer
Olof Tengblad
H. Weick
Mikhail Zhukov
Chalmers, Applied Physics, Subatomic Physics
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
0370-2693 (ISSN)
Vol. 679 3 191 - 196Subject Categories
Subatomic Physics
Roots
Basic sciences
DOI
10.1016/j.physletb.2009.07.044