Download - Linking Transitions (and Search for Superintruders) in the A 80 Region of Superdeformation
Linking Transitions (and Search for Superintruders) in the A80 Region of
Superdeformation
Nilsson Conf.Lund, Sweden17 June 2005
C. J. Chiara, D. G. Sarantites, M. Montero, J. O’Brien, O. L. Pechenaya, and W. Reviol, Washington University
R. M. Clark, P. Fallon, A. Görgen, A. O. Macchiavelli, and D. Ward, Lawrence Berkeley National Laboratory
W. Satuła, University of Warsaw
Y. R. Shimizu, Kyushu University
SD regions
A40 (linked)
A60(linked)
A190(linked)
A80(not linked!)
B. Singh, R. Zywina, R.B. Firestone, Nucl. Data Sheets 97,
241 (2002)
F. Lerma et al., PRC 67, 044310 (2003)84Zr
(linked)A130
TSD(linked)
A150(linked)
• 140-MeV 32S + 0.5-mg/cm2 58Ni 84Zr + 2p
• Gammasphere [102 Ge detectors]
• Microball [95 CsI(Tl) detectors] for charged particle detection; p80%, 70%
• Total of 2.2109 events of fold 5 or higher over 6 days.
Experimental details
0
1 0
2 0
3 0
coun
ts
S D 1 /4 0 5 2
1246
1527
1663
1808
1958
2113
2272
184516
46
1433
0
5
1 0
1 5
2 0
coun
ts
S D 1 /3 7 4 31563
135812
65
1527
1663
1808
1958
2113
2272
1402
181015
68
2 7 0 0 3 0 0 0 3 3 0 0 3 6 0 0 3 9 0 0 4 2 0 0E [k e V ]
0
1 0
2 0
3 0
4 0
5 0
coun
ts
S D 1 /S D 1
2780
3102
3464
*
3743
*
4052
*
2598
1 2 0 0 1 4 0 0 1 6 0 0 1 8 0 0 2 0 0 0 2 2 0 0 2 4 0 0E [k e V ]
0
5
1 0
1 5
2 0
coun
ts
S D 1 /3 4 6 4
1225
1363
1996
1808
1813
1555
1527
1663
1958
2113
Double-gated spectra of 84Zr
links
spectra
IS D 1 ~ 3 % I(2 +0 +)
IS D 2 ~ 1 % I(2 +0 +)
I(4 0 5 2 ) ~ 0 .9 % IS D 1
I(3 7 4 3 ) ~ 0 .7 % IS D 1
I(3 4 6 4 ) ~ 0 .4 % IS D 1
84Zr lev.sch
.
I0 = 25-
E1 M1/E2 E1
Compare with calculations using Cranked Strutinsky + Lipkin-Nogami pairing
5251 configuration previously assigned to SD1 based on Qt—now compare Ex, I as well:
0 .0 0 .5 1 .0 1 .5 2 .0 [M e V / ]
0
1 0
2 0
3 0
4 0
5 0
I x []
N D 1S D 1v acu u m5
251
(b )
0 1 0 2 0 3 0 4 0 5 0I [ ]
-2
0
2
4
6
8
E-0
.02I
(I+
1) [
MeV
]
N D 1S D 1v acu u m5
251
(a )
CSLN
Ex (near ND-SD crossing)
spin (except at alignments)
parity
Depopulation of the SD wellSD1 in 84Zr has weak decays to ND states, similar to the A=150,190 SD bands.
84Zr 152Dy* 192Pb†
* T.Lauritsen, PRL88, 042501 (2002)† A.N.Wilson, PRL90, 142501 (2003)
B(E1) ~10-6 W.u. ~10-6 W.u. ~10-7-10-8 W.u.
Weak decay-out explored with several statistical models, e.g.:• E.Vigezzi et al., PLB249,163 (1990)
• J.-z.Gu and H.A.Weidenmüller, NPA660, 197 (1999)
• D.M.Cardamone et al., PRL91, 102502 (2003)
Each relates S, N, d, FS with spreading width .
Compare 84Zr with results in A.N.Wilson, Prog. Theor. Phys. (Kyoto), Suppl.
154, 138 (2004):
nuclide I FS / S [eV]
192Pb 10+ 0.12 1.1107 511
12+ 0.66 9.8104 13194Pb 8+ 0.65 2.0104 0.28
10+ 0.9 3.3103 0.15194Hg 12+ 0.58 2.6102 0.025152Dy 28+ 0.6 6.0102 684Zr 25- < 0.2 > 1.1105 > 3700
27- 0.65 4.5 103 273
B(E1) [W.u.]
510-7
210-7
210-8
510-8
710-9
210-6
510-6
—
stat’l
Tunneling paths and barriers
• Calculate potential energy surfaces for fixed spins.
• Determine least-action path from SD min to ND well.
• Get barrier height in direction of path.
[K.Yoshida et al., NPA696, 85 (2001) and refs. therein.]
Compare 152Dy and 84Zr surfaces….
152Dy PES
Below the decay-out spin in 152Dy!
84Zr PES
Below the decay-out spin in 84Zr!
Barrier heights calculated along least-action paths from fixed-spin potential surfaces, as in K.Yoshida et al., NPA696, 85 (2001).
barriers
0 1 0 2 0 3 0 4 0I [ ]
0
1
2
3
4
barr
ier
heig
ht [
MeV
]
8 4Z r
1 5 2D y
1 9 2H g
Summary• “Full” characterization of an A80 SD band: Ex, I, Qt, B() [several neighbors studied too, but no luck linking!]
• Results are consistent with CS-LN calculations for 5251
configuration [esp. Ex(I) in crossing region]
• 84Zr SD1 has eclectic properties; similar to:
152Dy [spin, energy, B(E1)]
192Pb [strength of SD-ND coupling]
A60,130 regions [potential barriers]
• HF+SLy4 calcs at I=25 reveal many configs at different deformations with similar energies supports PES picture
C. J. Chiara, D. G. Sarantites, M. Montero, J. O’Brien, O. L. Pechenaya, and W. Reviol,
Washington U.
R. M. Clark, P. Fallon, A. Görgen, A. O. Macchiavelli, and D. Ward, LBNL
Theoretical support from
W.Satuła, U. of Warsaw
and
Y.R.Shimizu, Kyushu U.
C. J. Chiara, D. G. Sarantites, M. Montero, J. O’Brien, O. L. Pechenaya, and W. Reviol,
Washington U.
R. M. Clark, P. Fallon, A. Görgen, A. O. Macchiavelli, and D. Ward, LBNL
Theoretical support from
W.Satuła, U. of Warsaw
and
Y.R.Shimizu, Kyushu U.
The End