1. GT (  ) : Weak Process: Important roles in the Universe Combined Analysis of Mirror GT Transitions for the study of Proton-Rich Far-Stability Nuclei Yoshitaka FUJITA (Osaka Univ.) INPC 2007 / June 3-8  operator : simple operator (states with different shapes are not connected)

2. Direct Reactions with Light Projectiles Projectile 3 He Target Coulomb Excitation Elastic Scattering Inelastic Scattering Pick-up Stripping Charge-exchange Similarity with  decay! by Berta Rubio |i>  |f>  -int. Ejectile t

3. B(GT) derivation

4. GT (  ) : Weak Process: Important roles in the Universe  decay : Absolute B(GT), limited to low-lying state CE reactions : relative B(GT), Highly Excitation Region  decay  isospin symmetry  CE reaction Combined Analysis of Mirror GT Transitions for the study of Proton-Rich Far-Stability Nuclei Yoshitaka FUJITA (Osaka Univ.) INPC 2007 / June 3-8  operator : simple operator (states with different shapes are not connected)

5. Key Words High Energy Resolution in the Experiment Isospin Symmetry in the Nuclear Structure Combined Analysis of  -decay and CE Reaction

6. 58 Ni(p, n) 58 Cu E p = 160 MeV 58 Ni( 3 He, t) 58 Cu E = 140 MeV/u Counts Excitation Energy (MeV) 0 2 4 6 8 10 12 14 Comparison of (p, n) and ( 3 He,t) ０ o spectra Y. Fujita et al., EPJ A 13 (’02) 411. H. Fujita et al., PRC 75 (’07) 034310 SpSp J. Rapaport et al. NPA (‘83) T > states GTGR

7. **( 3 He,t): high resolution and sensitivity !

8. 9 Be( 3 He,t) 9 B spectrum (at various scales)

9. 9 Be( 3 He,t) 9 B spectrum (II) Isospin selection rule prohibits proton decay of T=3/2 state!

10. Isospin Selection Rule : in p-decay of 9 B + 9 B* p + 8 Be* 1p-1h p n T z : -1/2+ 0 = -1/2 T : 1/2+ 0 (low lying) = 1/2 T : 1/2+ 1 (higher Ex) = 1/2 & 3/2 *T=1 state in 8 Be is only above E x =16.6 MeV

11. 9 Be( 3 He,t) 9 B spectrum (III) 14.655 MeV T=3/2 state is very weak! Strength ratio of T=1/2 vs. 3/2, 3/2 - states: 140:1

12.  Shell Structure and Cluster Structure  n   p 9 Be 9B9B 9 Li 9C9C T=3/2 T z =3/2 T z =1/2T z =-1/2 T z =-3/2 Excited state: SM-like g.s.: Cluster-like suggestion by Y. Kanada-En’yo proton: p 3/2 closed neutron: p 3/2 closed

13. RCNP Ring Cyclotron Good quality 3 He beam (140 MeV/nucleon)

14. Grand Raiden Spectrometer Large Angle Spectrometer 3 He beam ( 3 He, t) reaction

15. Matching Techniques

16. **Isospin Symmetry Structure in Mass A Nuclei (Isobars)

17. Nuclei & Coin Coin back front Nuclei isospin T=1 triplet 50 24 Cr 26 T z = 1T z = -1 50 26 Fe 24 T z = 0 50 25 Mn 25

18. T=1 system 50 24 Cr 26 A=50 system Coulomb Energy: important 50 25 Mn 25 50 26 Fe 24

19. T=1 symmetry : Structures & Transitions 50 24 Cr 26 50 25 Mn 25 50 26 Fe 24

20. B(GT) values from Symmetry Transitions (A=26) Y. Fujita et al., PRC 67 (‘03) 064312

21. Supernova Cycle

22.  important K.L &G.M-P Rev.Mod.Phys.75(’04)819 (A,Z)=nuclei in the Cr, Mn, Fe, Co, Ni region pf -shell Nuclei ! Crucial Weak Processes during the Core Collapse

23. GT states in A=42-58 T z =0 nuclei starting from T z = +1 pf –shell nuclei

24. GT strengths in A=42-58 Log ft =3.2 [B(GT)=2.4]

25. GT strengths in A=42-58 GT-GR

26. GT states in A=42-58 T z =0 nuclei T. Adachi et al. H. Fujita et al. Y. Fujita et al.

27. **Derivation of “absolute” B(GT) values  -decay: T 1/2 and absolute B(GT) values but only for the low-lying states *( 3 He,t) reaction: highly-excited states can be accessed but only the relative B(GT) values

28. Mirror nuclei 46 Ti 50 Cr 54 Fe 50 Fe 54 Ni 46 Cr ß+ ( 3 He,t) N=Z T=1 Isospin Symmetry in pf-shell Nuclei 54 28 Ni 26 54 26 Fe 28 T z =0 T z =1 T z =-1 Leuven Valencia Surrey Osaka B. Rubio

29. Isospin Symmetry Transitions: 50 Cr( 3 He,t)  50 Mn   -decay 50 Fe Q EC =8.152(61) MeV T 1/2 =0.155(11) s 0.651 (Z,N)=(24,26)(25,25)(26,24)

30. 50 Cr( 3 He,t) 50 Mn

31. **Reconstruction of  decay from ( 3 He,t) ---assuming isospin symmetry ---

32. Simulation of  -decay spectrum  -decay feeding ratios are deduced ! Y. Fujita et al.PRL 95 (2005)

33. Absolute B(GT) values -via reconstruction of  -decay spectrum-  -decay experiment T 1/2 =0.155(11) s New value B(GT)=0.50(13) *20% smaller than deduced in the  -decay: 0.60(16) Absolute intensity: B(GT) Y. Fujita et al. PRL 95 (2005) B(F)=N-Z Relative feeding intensity from ( 3 He,t) t i =partial half-life

34. Mirror nuclei 46 Ti 50 Cr 54 Fe 50 Fe 54 Ni 46 Cr ß+ ( 3 He,t) N=Z T=1 Isospin Symmetry in pf-shell Nuclei 54 28 Ni 26 54 26 Fe 28 T z =0 T z =1 T z =-1 Leuven Valencia Surrey Osaka B. Rubio

35. Mirror nuclei 48V48V 52 Mn 56 Co 52 Co 56 Cu 48 Mn ++ ( 3 He,t) N=Z T = 2 Isospin Symmetry in pf-shell Nuclei 52 28 Ni 24 52 24 Cr 28 T z =0 T z =1 T z =-1 52 Ni T z =2 T z =-2 52 Cr 48 Cr 52 Fe 56 Ni 56 Fe 56 Zn 48 Ti 48 Fe by Y. Fujita, B. Rubio

36. Mirror nuclei 48V48V 52 Mn 56 Co 52 Co 56 Cu 48 Mn ++ ( 3 He,t) N=Z T = 2 Isospin Symmetry in pf-shell Nuclei 52 28 Ni 24 52 24 Cr 28 T z =0 T z =1 T z =-1 52 Ni T z =2 T z =-2 52 Cr 48 Cr 52 Fe 56 Ni 56 Fe 56 Zn 48 Ti 48 Fe by Y. Fujita, B. Rubio How is the T 1/2 value?

37. Comparison: (p, n) and ( 3 He,t) IAS g.s. 52 Cr(p, n) 52 Mn Ep =120 MeV D. Wang et al., NP A480 (’88) 285

38.  -decay Half-life T 1/2 -via reconstruction of  -decay spectrum- abs. B(GT) distribution from ( 3 He,t) B(F)=N-Z

39. 52 Ni  -decay Half-life T1/2  -decay exp. (PRC 49, 2440, ‘94) T 1/2 = 38 (5) ms [40.8(2) ms (’06 GANIL)] abs. B(GT) distribution [ 52 Cr( 3 He,t)] Q EC =11.88 MeV [  -decay + IMME (‘06)] B(F)=N-Z Isospin symmetry estimation T 1/2 = 39 (3) ms SM cal. (PRC 57, 2316, ’98) T 1/2 = 50 ms Mass formula (T. Tachibana et al.) T 1/2 = 35 ms Uncertainty of the Q-value should still be considered !

40. Analog Relationship (T=0,1,2) stable

41. 58 Ni(p, n) 58 Cu E p = 160 MeV 58 Ni( 3 He, t) 58 Cu E = 140 MeV/u Counts Excitation Energy (MeV) 0 2 4 6 8 10 12 14 Comparison of (p, n) and ( 3 He,t) ０ o spectra Y. Fujita et al., EPJ A 13 (’02) 411. H. Fujita et al., PRC 75 (’07) 034310 SpSp J. Rapaport et al. NPA (‘83) T=2

42. Analog Relationship (T=0,1,2) stable

43. Summary * Isospin Symmetry was introduced * High resolution of the ( 3 He,t) reaction allowed the comparison of analogous transitions * Properties of proton-rich “far-stability nuclei” is deduced by the combined analysis of  -decay and ( 3 He,t) reaction --- B(GT), Half-life T 1/2 --- **Accurate measurements of T 1/2 & Mass are very important** Collaboration of Stable beam facility and RI beam facility is very important!

44. High-Resolution Collaborations Gent (Belgium) : ( 3 He, t), (d, 2 He), (  ’) GSI, Darmstadt (Germany) : inverse kinematics ISOLDE, CERN (Switzerland) :  decay iThemba LABS. (South Africa) : (p, p’), ( 3 He, t) Jyvaskyla (Finland) :  decay Koeln (Germany) :  decay, ( 3 He, t), theory KVI, Groningen (The Netherlands) : (d, 2 He) Leuven (Bergium) :  decay LTH, Lund (Sweden) : theory Osaka University (Japan) : (p, p’), ( 3 He, t), theory Surrey (GB) :  decay TU Darmstadt (Germany) : (e, e’), ( 3 He, t) Valencia (Spain) :  decay Michigan State University (USA) : theory, (t, 3 He) Muenster (Germany) : (d, 2 He), ( 3 He,t) University of Tokyo : theory