Unexpected behavior of heavy-ion fusion cross sections at extreme sub-barrier energies.
The excitation function for fusion evaporation in the (60)Ni+ (89)Y system was measured over a range in cross section covering 6 orders of magnitude. The cross section exhibits an abrupt decrease at extreme sub-barrier energies. This behavior, which is also present in a few other systems found in the literature, cannot be reproduced with present models, including those based on a coupled-channels approach. Possible causes are discussed, including a dependence on the intrinsic structure of the participants.
Jiang
C L
CL
Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
Esbensen
H
H
Rehm
K E
KE
Back
B B
BB
Janssens
R V F
RV
Caggiano
J A
JA
Collon
P
P
Greene
J
J
Heinz
A M
AM
Henderson
D J
DJ
Nishinaka
I
I
Pennington
T O
TO
Seweryniak
D
D