Properties of the 7He ground state from 8He neutron knockout
Artikel i vetenskaplig tidskrift, 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.
Författare
Yuliya Aksyutina
Chalmers, Teknisk fysik, Subatomär fysik
Håkan T Johansson
Chalmers, Teknisk fysik, Subatomär fysik
T. Aumann
K. Boretzky
M. J. G. Borge
A. Chatillon
L.V. Chulkov
D. Cortina-Gil
U. Datta Pramanik
H. Emling
Christian Forssen
Chalmers, Teknisk fysik, Subatomär fysik
H. O. U. Fynbo
H. Geissel
G. Ickert
Björn Jonson
Chalmers, Teknisk fysik, Subatomär fysik
R. Kulessa
C. Langer
Mattias Lantz
Chalmers, Teknisk fysik, Subatomär fysik
T. LeBleis
Anton Lindahl
Göteborgs universitet
K. Mahata
Mikael Meister
Chalmers, Teknisk fysik, Subatomär fysik
G. Münzenberg
Thomas Nilsson
Chalmers, Teknisk fysik, Subatomär fysik
Göran Hugo Nyman
Chalmers, Teknisk fysik, Subatomär fysik
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, Teknisk fysik, Subatomär fysik
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
0370-2693 (ISSN)
Vol. 679 3 191 - 196Ämneskategorier
Subatomär fysik
Fundament
Grundläggande vetenskaper
DOI
10.1016/j.physletb.2009.07.044