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Lifetime measurements in 128 Cs and 132 La as a test of chirality. Julian Srebrny Nuclear Physics Division Institute of Experimental Physics Warsaw University. Kazimierz Dolny September 2005. Three angular momentum vectors can form two systems of different handedness.
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Lifetime measurements in 128Cs and 132La as a test of chirality Julian Srebrny Nuclear Physics Division Institute of Experimental Physics Warsaw University Kazimierz Dolny September 2005
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 maximumoverlap. - one hole takes minimum overlap ( angular momentum R ) ( angular momentum p ) (angular momentum n-1) example: 132La75 and 128Cs73 p(h11/2) 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
HIL Warsaw Candidates for chiral partner bands identified in 10 odd-odd nuclei in A130
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
detector N g E g recoils Thick target Beam ions Doppler Shift Attenuation Method Doppler shifts, attenuated during the stopping process in the target, are analysed.
Results of transition probabilities for 132La Int.J.Mod.Phys. E13, 243 (2004) E.Grodner, J.Srebrny, Ch.Droste, T.Morek, A.Pasternak, J.Kownacki Absolute transition probabilities are different in both bands. Transition probabilities in side band are 20 times smaller than in the yrast band.
preliminary results in E.Grodner et al. HIL An..Rep.2004 http:/www.slcj.uw.edu.pl/reports/Report04.pdf The newest results for 128Cs comparison with 132La electromagnetic properties similar in both bands in 128Cs. chiral symmetry can be broken.
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 Frauendorf, Meng 1997 interpretation of 134Pr data 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 132La Warsaw Cyclotron and OSIRIS II,DSAM 2003 6. 128Cs lifetime measurements Warsaw Cyclotron and OSIRIS II,DSAM 2004 128Cs– the best case interpreted within chiral symmetry braking 2005 The important role of smaller accelerators for nonstandard idea
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
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