Lifetime measurements in 128Cs and
as a test of chirality
Julian Srebrny
Nuclear Physics Division
Institute of Experimental Physics
Warsaw University
Kazimierz Dolny
September 2005
132La
Three angular momentum vectors can form
two systems of different handedness
“O” operator
acting on
3 aplanar
vectors does
change the
handedness.
“O” operator acting
on 3 vectors in a
plane,
does not change
the handedness.
Where it can be find in nuclear case ?
- three-axial even even core
- one particle takes maximum overlap.
- one hole takes minimum overlap
example:
p(h11/2)
( angular momentum R )
( angular momentum p )
(angular momentum n-1)
132La
75
and
128Cs
73
 n-1(h11/2 )  three-axial core
intrinsic system
Restoration of the chiral symmetry
in the laboratory reference frame
forms two nearly degenerate
bands: chiral partner bands
Candidates for chiral partner bands identified
in 10 odd-odd nuclei in A130
HIL Warsaw
Doppler Shift Attenuation Method
Experimental facility
10 AntiCompton Shielded
germanium spectrometers
Heavy Ion laboratory Warsaw
University
U200P Cyclotron
Heavy Ion laboratory
University of Warsaw
Reactions
122Sn
(14N,4n)132La
10mg/cm2
70MeV
122Sn
(10B,4n)128Cs
40mg/cm2
55MeV
Ge-Ge coincidences
Doppler Shift Attenuation Method
Doppler shifts, attenuated during the
stopping process in the target, are analysed.
detector
N g
E
recoils
Thick target
Beam ions
g
Results of transition probabilities for
Int.J.Mod.Phys. E13, 243 (2004)
E.Grodner, J.Srebrny, Ch.Droste,
T.Morek, A.Pasternak, J.Kownacki
Intraband
transitions
100
B(E2,I->I-2) [W.u.]
Absolute transition probabilities are
different in both bands.
132La
132
La
10
yrast band
side band
1
Transition probabilities in side band
are 20 times smaller than
in the yrast band.
12
14
16
I [h]
18
20
The newest results for
comparison with
electromagnetic
properties similar
in both bands in
128Cs.
chiral symmetry
can be broken.
132La
128Cs
preliminary results in
E.Grodner et al. HIL An..Rep.2004
http:/www.slcj.uw.edu.pl/reports/Report04.pdf
CQPHC results for
128Cs
theoretical
calculations done
in frame of
CQPHC model core properties
taken from 128Xe
B(M1)
staggering is
reproduced by
the CQPHC
calculations
Phys. Rev. C67, 044319 (2003)
T. Koike, K. Starosta, C.J. Chiara, D.B. Fossan, D.R. LaFosse
E. Grodner, I. Zalewska, T. Morek, J. Srebrny, Ch. Droste,
M. Kowalczyk, J. Mierzejewski, M. Sałata.
Institute of Experimental Physics, Warsaw University, Warsaw, Poland
A. A. Pasternak
A. F. Ioffe Physical Technical Institute RAS, St. Petersburg, Russia
P.Olbratowski, J. Dobaczewski, S. G. Rohoziński, W. Satuła
Institute of Theoretical Physics, Warsaw University, Warsaw, Poland
J. Kownacki, M. Kisieliński, A. Kordyasz, P. Napiorkowski,
M.Wolińska-Cichocka
Heavy Ion Laboratory of Warsaw University, Warsaw, Poland
L. Nowicki, R. Ratajczak,
R. Kaczarowski, W. Płóciennik, E. Ruchowska, A. Wasilewski
The Andrzej Sołtan institute for Nuclear Studies, Otwock-Świerk, Poland
1. New phenomena of chiral symmetry breaking
first theoretical prediction
interpretation of 134Pr data
Frauendorf, Meng 1997
Petrache et al. 1996
2. Experimental identification of chiral doublets
based on energy levels only- about 10 cases for A  130 2001-2003
3. CPHC model formulated and firstly applied to 132La
K. Starosta et al.
2002
4. First self-consistent HF chiral solutions
P. Olbratowski et al.
2002
5. First lifetime measurements in supposed chiral bands
Warsaw Cyclotron and OSIRIS II,DSAM
6.
128Cs
lifetime measurements
Warsaw Cyclotron and OSIRIS II,DSAM
132La
2003
2004
128Cs
– the best case interpreted
within chiral symmetry braking
2005
The important role of smaller accelerators for nonstandard idea
Later on some usefull foils
not presented at the Workshop
Lifetimes in
132La
All lifetimes are in 0.5-1.5ps
range.
More than 20 lifetimes were
measured.
New band was discovered
Lifetimes were recalculated
to more than 40 absolute
reduced transition
probabilities
Stopping power parameters
for 132La
Stopping power parameters can
be obtained from the velocity
distribution of recoils
Target thickness comarable with
recoils range
Observed transition from state
living more then few
picoseconds
Velocity distribution depends
only on the stopping process
Stopping power parameters
for 132La
reference paper on triaxiality in A = 130 region of nuclei
Nucl.Phys. A292, 66 (1977)
S.G.Rohozinski, J.Dobaczewski, B.Nerlo-Pomorska, K.Pomorski, J.Srebrny
Energy splitting between partner bands
This picture
shown in 2003
supposed to proof
the chirality discovery
in atomic nucleus
Phys.Rev. C65, 044328 (2002)
K.Starosta, C.J.Chiara, D.B.Fossan,
T.Koike, T.T.S.Kuo, D.R.LaFosse,
S.G.Rohoziński, Ch.Droste, T.Morek,
J.Srebrny