(68)(28)Ni(40): Magicity versus superfluidity.
The neutron-rich (66,68)Ni have been produced at GANIL via interactions of a 65.9A MeV 70Zn beam with a 58Ni target. Their reduced transition probability B(E2;0(+)(1)-->2+) has been measured for the first time by Coulomb excitation in a (208)Pb target at intermediate energy. The B(E2) value for (68)Ni(40) is unexpectedly small. An analysis in terms of large scale shell model calculations stresses the importance of proton core excitations to reproduce the B(E2) values and indicates the erosion of the N = 40 harmonic-oscillator subshell by neutron-pair scattering.
Sorlin
O
O
Institut de Physique Nucléaire, IN2P3-CNRS, F-91406 Orsay Cedex, France.
Leenhardt
S
S
Donzaud
C
C
Duprat
J
J
Azaiez
F
F
Nowacki
F
F
Grawe
H
H
Dombrádi
Zs
Z
Amorini
F
F
Astier
A
A
Baiborodin
D
D
Belleguic
M
M
Borcea
C
C
Bourgeois
C
C
Cullen
D M
DM
Dlouhy
Z
Z
Dragulescu
E
E
Górska
M
M
Grévy
S
S
Guillemaud-Mueller
D
D
Hagemann
G
G
Herskind
B
B
Kiener
J
J
Lemmon
R
R
Lewitowicz
M
M
Lukyanov
S M
SM
Mayet
P
P
de Oliveira Santos
F
F
Pantalica
D
D
Penionzhkevich
Yu-E
YE
Pougheon
F
F
Poves
A
A
Redon
N
N
Saint-Laurent
M G
MG
Scarpaci
J A
JA
Sletten
G
G
Stanoiu
M
M
Tarasov
O
O
Theisen
Ch
Ch