High spin physicsachievements and perspectives
S. Frauendorf
IRP, Research Center
Dresden-Rossendorf, Germany
and
Department of Physics
University of Notre Dame, USA
The frontiers
fission 1)Path to fission
I
6)The future
3)Isospin multiplets
p-dripline
5) Weak symmetry breaking
A=130
2) Triaxiality
N-Z
n-dripline Terra incognita
SHE
A
4) Bands and isomers
around A=250
1)Path to fission
New shells: TSD
Triaxial Strongly deformed
Symmetries decide: irregularbandsspin-parity sequence
Disappearance and recurrence of rotational bands
Courtesy M. Riley
Courtesy M. Riley
E.Paul et al. PRL 98, 012501 (2007)
First evidence
for
hyperdeformation?
the Z=70,71 N=94,97 gaps
wobblers
Courtesy M. Riley
nwobble  0
nwobble  1
nwobble  2
p-h excitation
Why are they
different?
163
163
Lu
wobbling
Tm
no
wobbling
2) Triaxiality
Spectroscopy of fragments
From spontaneous Cf fission
X.Y. Luo et al., PLB, in review
I. Stefanescu et al., NPA, in press
2
E(I)-0.017I [MeV]

J
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
Egr
Egaer
Egaor
E1r
E2r
p=112
chiral
nwobble  2
Ru
nwobble  1
p=+
0
2
4
nwobble  0
6
8
10 12 14 16 18 20 22
I
wobbler
Consequence of chirality: Two identical rotational bands.
Best case of chirality so far: chiral vibrations in
h112 / 2h111/ 2
S. Zhu et al.
Phys. Rev. Lett. 91, 132501 (2003)
135
60
Nd75
15
Chiral vibrations in 135-Nd
TAC+RPA calculations
Mukhopadhyay, Almehed
et al.
Phonon is mainly orientation fluctuations
PRL 99, 172501 (2007)
Same inband transition rates - Good agreement with experiment
16
135-Nd Transition rates
in-band
cross band
17
3)Isospin multiplets
4) Bands and isomers around A=250
Pretty robust
Condensation of
Octupole phonons
1.0
n=3
0.8
0.6
+
E'n-E'0
0.4
n=2
j=3 phonon
condensation
n=1
0.2
0.0
n=0
-0.2
Two phonon
One phonon
+
-0.4
0.00
0.05
0.10
0.15

X. Wang, R.V.F. Janssens, I.
Wiedenhoever et al. to be
published.
Preliminary
27
5) Weak symmetry breaking
• Chiral vibrations
• Rotation induced condensation
of octupole phonons
• Tidal waves
• How does the nucleus rotate?
Rotation induced condensation
of octupole phonons
S. Frauendorf
Two components: Quadrupole +Octupole
Phys. Rev. C 77, 021304 (07)
0.3
2=/2
Th
3=/3
90
[MeV]
0.2
0.1
0.0
130
132
134
136
N
138
140
23
Weak coupling
1.0
n=3
0.8
0.6
+
E'n-E'0
0.4
n=2
j=3 phonon
condensation
n=1
0.2
0.0
n=0
-0.2
Two phonon
One phonon
+
-0.4
0.00
0.05
0.10
0.15

X. Wang, R.V.F. Janssens, I.
Wiedenhoever et al. to be
published.
Preliminary
27
Intermediate coupling
missing
27
0.5
0.4
226
E[MeV]
0.3
Strong coupling
Th
0.2
0.1
0.0
-0.1
-0.2
0
5
10
15
20
25
30
(I-1/2)[ h]
I
20
18
226
Th
16
+
14
12
10
8
6
4
2
0
0.00 0.05 0.10 0.15 0.20 0.25 0.30
h[MeV]
28
1.Weakly oriented nuclei – tidal waves
S. Frauendorf, Y. Gu, arXiv 0709.0254, PRL, in preparation
Mean field:
rigid spherical
soft
rigid deformed
-condensation of
quadrupole phonons
-very soft rotor
Tidal wave
Yrast line
irregular
multi p-h
4
regular
regular
w weakly increases with I w proportional to I
How does orientation come about?
Deformed density / potential
Orientation of the gyroscopes
Nucleonic
orbitals –
gyroscopes
Deformed potential aligns the
partially filled orbitals
Partially filled orbitals are
highly tropic
1.0
overlap
0.8
0.6
0.4
Nuclus is oriented –
rotational band
0.2
Well deformed
174
Hf
0.0
-90
0
90

180
270
5
How does the nucleus rotate?
Angular momentum is generated
by alignment of the spin of the
orbitals with the rotational axis
Gradual – rotational band
Abrupt – band crossing, no bands
Moments of inertia for I>20
(no pairing) differ strongly from
rigid body value
Microscopic cranking
Calculations do well in
reproducing the moments
of inertia.
With and without pairing.
M. A. Deleplanque et al.
Phys. Rev. C69, 044309 (2004)
7
What have we learned?
• Liquid drop + shell structure in rotating WS
– like potential account for energies and
lifetimes. Time-odd terms of the mean
field?
• Deviations from classical droplet are
dramatic.
• Symmetries of the mean field play a
central role
• Dynamical (weak) symmetry breaking is
common.
6)The future
Combination of large Gamma ray arrays
with stable and radioactive beams
The challenges (incomplete)
fission Map out the new shells
I
Ergodic bands
(Mottelson, Matsuo,Yoshida)
Dynamics of angular
momentum reorientation
Rotation induced T=0 pairing?
p-dripline
Cold proton emission from high spin states
A=130
N-Z
SHE
A
Increased stability of
High spin isomers
n-dripline Terra incognita Decoupling of mass from charge
Increased stability of K-isomers
Single particle states from isomers