Measurement of excited states in (40)Si and evidence for weakening of the N=28 shell gap.
Excited states in (40)Si have been established by detecting gamma rays coincident with inelastic scattering and nucleon removal reactions on a liquid hydrogen target. The low excitation energy, 986(5) keV, of the 2(1)(+) state provides evidence of a weakening in the N=28 shell closure in a neutron-rich nucleus devoid of deformation-driving proton collectivity.
Campbell
C M
CM
National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA.
Aoi
N
N
Bazin
D
D
Bowen
M D
MD
Brown
B A
BA
Cook
J M
JM
Dinca
D-C
DC
Gade
A
A
Glasmacher
T
T
Horoi
M
M
Kanno
S
S
Motobayashi
T
T
Mueller
W F
WF
Sakurai
H
H
Starosta
K
K
Suzuki
H
H
Takeuchi
S
S
Terry
J R
JR
Yoneda
K
K
Zwahlen
H
H