News on 12C from
-decay studies
• What’s left to study in 12C ?
• New results from -decay studies
Hans O. U. Fynbo
Department of Physics and Astronomy
University of Aarhus, Denmark
Tokyo, June 4, 2007
What’s left to study in 12C ?
(15.3)
15.11
1+
14.08
13.35
12.71
4+
(2-, 4-)
11.83
(11.2) 10.84
2-
10.3
9.641
(2+)
1+
1-
(2+)
10.27
(0/2+)
2+
3-
Ongoing theoretical interest :
0+
7.65
a+a+a
7.275
4.4389
0
Levels according to TUNL
7.377
0+
7.275
•Ab-initio VMC or 8Greens-Function
MC
Be+a
a+a+a
•No core shell-model QM-060, QW-070
•AMD/FMD
F1-1, F10-1, QW-062
2+
•Algebraic calculations Bijker &Iachello
•Cluster models QM-054, QT-021,QT-039,
QW-015, QW-017
•Condensate states ? Q5-5, F3-2, QT-050-51
•Astrophysics
0+
Why is it experimentally challenging ?
10B(3He,p)12C
Talk : O. Tengblad (F1-3)
Posters : M. Alcorta, O. Kirsebom (QT-206))
-decay approach : Selection rules
(15.3)
(2+)
15.11
1+
12.71
1+
1+
(2+)
(11.5)
10.3
7.6542
0,2+
0+
7.275
4.4389
0
See also talk of M.Itoh (F11-7)
2+
0+
1+
-decay approach : Earlier work
Phys. Rev. 111 (1958) 567
Phys. Rev. 130 (1963) 1953
12N/12B+X
a,
Beam
Target
Nucl. Phys. A89 (1966) 401
Direct Kinematics+ISOL
12C/11B
12N/12B+X
p/d
Magnet
12N/12B
a
Nucl.Phys. A738 (2004) 59.
Nucl.Phys. A760 (2005) 3.
Nature 433 (2005) 136.
Talks : J.Äystö (A1-4), L. Fraile (J2-2), H. Frånberg (J2-7)
Inverse Kinematics+Separator
12N/12B
12N/12B+X
Magnets
12C/11B
p/d
Talk : H.Wilschut (J2-5) , Poster : R.Raabe (QT-011)
a
ISOL Experiment 2004
L.M. Fraile & J.Äystö, NIMA513 (2003) 287.
12N/12B
Talks : J.Äystö (A1-4), L. Fraile (J2-2), H. Frånberg (J2-7)
a
0+, 2+ ?
1+
0+, 2+ ?
Christian Diget
KVI Experiment 2006
K. Jungmann
H. Wilschut
Talk J2-5.
12N/12B
R.Raabe, QT-011
a
0+
0+,
2+
?
1+
0+, 2+ ?
1+
Solveig Hyldegaard
Comparison of the two Experiments
1.43(7)%
2.7(4) %
KVI
#12N =
8.8107
IGISOL
#12N =
1.2108
0.55(2)%
0.56(7)%
0.46(15)%
0.122(7)%
0.108(15)%
0.28(8)%
a
0+, 2+ ?
1+
Christian Diget
a
0+
0+, 2+ ?
1+
Solveig Hyldegaard
Comparison of the two Experiments
0.59(4)%
1.2(3)%
0.108(4)%
0.116(13)%
0.08(2)%
KVI
#12B =
9.3107
IGISOL
#12B =
9.7108
3.0(2)10-4%
-4%
+
3.4(6)
10
1
Comparison of the two Decays
12B
12N
fT1/ 2
1
ft 

B.R. M if
2
Comparison of the two Decays
B.R.
ft 
 M if
fT1/ 2
1

2
R-matrix fits : Presently only to IGISOL and 8Be(gs)
Nucl.Phys. A738 (2004) 59.
Nucl.Phys. A760 (2005) 3.
Nature 433 (2005) 136.
0+
2+
0+
Work in progress to include 8Be(2+) and new data.
Collaborators
• C. Aa. Diget, H. Jeppesen, S.Hyldegaard, H.H. Knudsen, O. Kirsebom,K. Riisager,
Department of Physics and Astronomy, Århus University, Denmark
• B. Jonson, M. Meister, T. Nilsson, G. Nyman, K. Wilhelmsen,
Fundamental Physics, Chalmers University of Technology, Gothenburg, Sweden
• T. Eronen, W. Huang, J. Huikari, A. Jokinen, A. Kankainen, I. Moore,
A. Nieminen, H. Penttilä, S. Rinta-Anttila, Y. Wang, J. Äystö, A. Saatamoinen,
K. Perajärvi, Department of Physics, University of Jyväskylä, Finland
• M. Alcorta, R. Boutami, M.J.G. Borge, L. Fraile, M. Madurga, O. Tengblad,
M. Turrion, Instituto Estructura de la Materia, CSIC, Madrid, Spain
• B. Fulton, S.Fox
University of York, United Kingdom.
Thank you for your attention !
• F.C. Barker
Australian National University
• K. Jungmann, S. Brandenburg, H. Wilschut, P. Dendooven, A. Rogachevskiy,
G. Onderwater, E. Traykov, M. Sohani, KVI, Groningen, The Netherlands
• R. Raabe, J. Bücherer, Piet van Duppen, Mark Huyse, IKS, Leuven, Belgium