Beta decay and Structure of Exotic Nuclei near 78Ni
Alexander Lisetskiy
NSCL,JINA,MSU
Motivation
• Astrophysical r-process
• Recent experimental progress for neutron-rich nuclei • Lack of shell model effective interactions for exotic regions
Where are exotic nuclei?
Shell Model Effective Interaction
T=1 interaction and SPE sources
Ni isotopes +N=50 isotones
G-matrix Bonn-Cpotential
56Ni core
A. F. Lisetskiy, B. A. Brown, M. Horoi PRC 70, 044314, (2004)
Single particle energies
5757NiNi 7777NiNi 7979CuCu 9999InIn
p3/2
f5/2
g9/2
p1/2
g9/2
-1
p1/2-1
f5/2-1
p3/2-1
f5/2-1
p3/2-1
p1/2-1
g9/2
-1
g9/2
p1/2
f5/2
p3/2
Cu: spectra and magnetic moments
A.F. Lisetskiy, B. A. Brown, M. Horoi, EPJ direct (2005)
L. Weissman & U. Koester,Private communication
Ni: Beta-decay properties
75Ni and 78Ni: B(GT) distribution
T=0 interaction and SPE modifications
Cu isotopes + N=49,48 isotones
jp = jn + jn’Vmon(jp,jn’)
New Single Particle Energies
5757NiNi 7777NiNi 7979CuCu 9999InIn
p3/2
f5/2
g9/2
p1/2
g9/2
-1
p1/2-1
f5/2-1
p3/2-1
f5/2-1
p3/2-1
p1/2-1
g9/2
-1
g9/2
p1/2
f5/2
p3/2
Ni: New Beta-decay results
P. T. Hosmer et al., PRL 94, 112501 (2005)
75Ni: New B(GT) distribution
Old results
New results
76Ni: New B(GT) distribution
Old results
New results
78Ni: Microscopic structure of GT strength distribution
Cu isotopes
P. T. Hosmer, in preparation …
Summary
• Improved shell model effective interaction for the p3/2p1/2f5/2g9/2 space in action
• Good agreement between theory and experiment for Ni isotopes indicates reliability of the interaction
• Good description of T1/2 and Pn values for Cu isotopes
• Beta decay data provide important information where nuclear structure data are missing
• Extended studies of Cu, Zn, Ga, Ge