1. Search for chiral doublet structures in odd-A 79 Kr with the Hyperball2 array @ CYRIC CYRIC/Tohoku University J.Timar ATOMKI (Hungary) K. Starosta (MSU) R. Wadsworth Univ. of York (U.K) G. Rainovski (SUNY at Stony Brook)

2. 134 PrChirality

3. A~130 Odd-Odd (  h 11/2 h 11/2 ) 132 Cs, 130 Cs, 128 Cs, 126 Cs, 124 Cs 134 La, 132 La, 130 La 134 Pr, 132 Pr 136 Pm 140 Eu, 138 Eu Odd-A (  (h 11/2 ) 2 h 11/2 ) 135 Nd A~105 Odd-Odd (  g 9/2 h 11/2 ) 106 Ag, 106 Rh, 104 Rh, 102 Rh 100 Tc (P.Joshi’s Talk), Odd-A (  g 9/2  h 11/2 ) 2 ) 105 Rh, 103 Rh A~190 Odd-Odd (  h 9/2 i 13/2 ) 188 Ir ( D. L. Balabanski et. al., Phys. Rev. C 70, 044305 (2004)) A~80 ( unexplored ) Odd-Odd (  g 9/2 g 9/2 ) 80 Br(?), Odd-A (  g 9/2 ) 2  g 9/2 )) 79 Kr(?)

4. Doublet bands in odd-even 135 60 Nd 75 S. Zhu et al., PRL 91(2003) 132501. Spin [ħ] Energy [MeV]

5. Doublet bands in 105 45 Rh 60 J. Timar et al., PLB598,178 (2004). Spin [ħ] Energy [MeV]

6. Possible chiral structure in 79Kr G.D. Johns et. al, Phys. Rev. C 50,2786 (1994)  (g 9/2 ) 2 g 9/2

7. Hyperball2 experiment @ CYRIC (Being assembled) 70 Zn( 13 C,4n) 79 Kr @58MeV or 65 Cu( 18 O,p3n) 79 Kr @65MeV [ Single Ge (60%) +BGO ] x 14 + [ Clover type Ge (125%) +BGO ] x 6 → Photopeak efficiency ~ 5% at 1 MeV UMEM/Double buffering

8. 70 Zn + 13 C

9. 79 Kr yield estimate σ=~500mb Beam intensity I : 2pnA Target thickness S: 1mg/cm 2 Average number of gamma rays emitted: 10 Total photo peak efficiency of Hyperball2: 5% (79Kr: 54K particle/second)X10X(0.05) 3 X24x3600 ~6 million g-g-g coincidence in 79 Kr per day 24million g-g-g coincidence in requested 12 shifts equivalent to 72 g-g unfolded event

10. Excitation function measurement and preliminary experiment at Stony Brook Excitation function measurements for two reactions at Van de Graaff Tandem/LINAC facility Beam time scheduled in April (Timar Janos ATOMKI, Hungary & Stony Brook NATO grant) One week in-beam g-g coincident measurement with better of the two reactions. (6 BGO suppressed Ge array) Preliminary analysis

11. In-beam experiment preparation Hyperball2 frame/Rail (March assembly) Target chamber (in the making) BGO counters (April assembly) Cryogenic system/LN 2 transport (in progress) Power issue DAQ

12. Possible chiral structure in 79Kr G.D. Johns et. al, Phys. Rev. C 50,2786 (1994)  (g 9/2 ) 2 g 9/2 50% 5~10% 1~2.5%

13. In-beam experiment with Hyperball2 Advantages –Large total photo peak efficiency (g-g-g coincidence) –Transistor reset type (high counting rate→ high intensity beam) –BGO as a multiplicity filter (12x6+6x14=156 elements) –Clover detector as Compton polarimeter Disadvantages –Few angles (detectors placed mostly around 90º) → lower angular correlation sensitivity

14. Rate estimate Total cross section σ=~1b Beam intensity I : 2pnA Target thickness S: 1mg/cm 2 Average number of gamma rays emitted: 10 ~10 6 gamma/second

15. Ge det. status at glance Eurisys Single Crystal Ge (r.e. ~60%) X 5 Ortec Single Crystal Ge (r.e. ~60%) X 10 Eurisys Clover type Ge X 6 –(r.e. ~20%, add-back 125%) Total X 21 Ready for use X 12 Being Repaired X 6 (G2,G3,G14,S/N1,S/N3,S/N4) Problematic X 3 (G1,G9,G1)

16. Target chamber for in-beam experiments with Hyperball2 at CYRIC

17. Important theme of nuclear structure studies Nuclear deformation Spontaneous symmetry breaking Collective degree of freedom –Nuclear Shape Coupling of single particle degree and collective degree of freedom

18. 132 Ce Rotation

19. Unique Parity Orbit SHOSHO+ls N=0 N=1 N=2 N=3 N=4 N=5 Simple Harmonic Oscill. (SHO)  =(-1) N SHO+ls Major shell consisting of majorities of normal parity and unique parity orbitals. The  h 11/2  h 11/2 confg. is comprised of two unique parity orbitals. 0s 0s 1/2

20. Possible realization for chiral geometry: odd-odd nuclei in the A~130 region jj j R long intmd. short Z=~55 N=~75 Triaxial mass distribution (shape). Fermi level lies low in proton h 11/2 subshell, high in neutron h 11/2 subshell. Collective rotation of triaxial rotor with irrotational flow moment of inertia.

21. Analysis DAQ –UMEM double buffering ( 木下） –root based online analysis ( 鈴木） On/Off-line analysis –Radware (xmgf3, matrix, cube, hypercube) Polarization sensitivity –PDCO (fusion evaporation) –GOSIA (Coulomb excitation)

22. Chiral Geometry in Nuclei K.Starosta Phys. Rev. Lett. 86, 971 (2001). Mutually orthogonal coupling of three angular momenta in odd-odd nuclei

23. Systematics of odd-odd Rh isotopes near A~104 C. Vaman et al., PRL92, 032501 (2004) P. Joshi et al., PLB 595,135 (2004) πg 9/2 h 11/2

24. Doublet bands in odd-even 103 Rh and 105 Rh near 104 Rh C. Vaman and J. Timar et al., to be submitted 103 Rh 105 Rh