1. Down and Up Along the Proton Dripline Heavy One-Proton Emitter Light One-Proton Emitter Light Two-Proton Emitter Heavy Two Proton Emitter

2. Proton Radioactivity -60 -40 -20 0 20 40 Centrifugal (l=5) Coulomb Nuclear Radius (fm) V (MeV) 20 40

3. Strong Influence on Angular Momentum V (MeV) l=0 l=5 T 1/2 (l=0) = 3  s T 1/2 (l=5) = 81ms E=1.25 MeV Radius (fm) -40 -20 0 20 4080 60 Lu 151 71 80

4. Heavy Proton Emitter &Long lifetimes due to Coulomb and angular momentum barrier &Produce in fusion evaporation reactions or fragmentation &Separate and subsequently stop in a detector for identification &Use segmented silicon strip detectors for a delayed decay

5. 1p Separation Energies (Odd p-numbers) T. Radon et al., Pramana 53 (1999) 69

6. 1p Separation Energies (Even p-numbers) T. Radon et al., Pramana 53 (1999) 69

7. Structure and Deformed Emitters C. J. Gross et al. 113 Cs A. A. Sonzogni et al. 131 Eu, 141 Ho, 145 Tm J. Uusitalo et al. 155 Ta K. Rykaczewski et al. 140 Ho, 141 Ho T. N. Ginter et al. 150 Lu K. S. Toth et al. 151 Lu P. J. Woods and C. N. Davids, Annu. Rev. Nucl. Part. Sci. 47 (1997) 541

8. Q-Values and Branching Ratios R. J. Irvine et al., Phys. Rev. C 55 (1997) R1621 C. N. Davids et al., Phys. Rev. C 55, (1997) 2255 161 Re 167 Ir

9. Where is the Proton Dripline?

10. “Short”-Lived Proton Emitters C.R. Bingham et al.

11. 100 Sn K. Sümmerer et al., Nucl. Phys. A616 (1997) 341c

12. rp - Process 5352515049 525150 49484746 Co Fe 45 8079 8382 Zr Nb Mo 81 8483 M. F. Mohar et al., Phys. Rev. Lett. 66 (1991) 1571 B. Blank et al., Phys. Rev. Lett. 77 (1996) 2893 B. Blank, J. Phys. G 24 (1998) 1385

13. New Isotopes Along the Dripline B. Blank, J. Phys. G 24 (1998) 1385 B. Blank et al., Phys. Rev. Lett. 77 (1996) 2893

14. Prompt Decay from a Well-Deformed Band  p D. Rudolph et al., Phys. Rev. Lett. 80 (1998) 3018

15. First Proton Radioactivity 7/2 - 3.04 0 19/2 - 247 ms 0 3.19 (7/2 - ) 12 10 8 6 4 2 0 Energy (MeV) 0.84 0 0+0+ 2+2+ (19/2 - ) ++ 26 Fe 2 7 5353 26 Fe 2 6 5252 27 Co 26 5353 1.5% Joseph Cerny and J. C. Hardy, Annu. Rev. Nucl. Part. Sci. 27 (1977) 333

16.  -Delayed Proton Emitters S. Czajkowski et al., Nucl. Phys. A628 (1998) 537

17. Light Proton Emitter &(Very) short lifetimes due to small Coulomb and no or very small angular momentum barrier (l=0,1,2) &Produce in transfer reactions or fragmentation &Identify by complete kinematic reconstruction in flight

18. 151 Lu and 12 O

19. Definition of Radioactivity Joseph Cerny and J. C. Hardy, Annu. Rev. Nucl. Part. Sci. 27 (1977) 333 “…should lead to lifetimes longer than 10 -12 sec, a possible lower limit for the process to be called radioactivity.” “…should lead to lifetimes longer than 10 -12 sec, a possible lower limit for the process to be called radioactivity.”

20. Search for Di-Proton Emitters &Predicted by Goldansky in 1960 &Until recently (?) elusive &In-Flight Decay (Short lifetimes) & Ground State & Excited States & Resonance Scattering & Coulomb Excitation & Neutron-Stripping &Implantation/Decay (Long lifetimes) & Beta-Delayed Emitters & Ground-State Emitters

21. Potential Two Proton Emitter

22. Definitions Di-Proton Decay Sequential Decay 12 O 11 N+p 10 C+p+p 12 O 10 C+2p 10 C+p+p 12 O 10 C+2p 11 N+p 12 O 10 C+2p 11 N+p Simultaneous Decay 12 O 10 C+p+p 12 O 10 C+2p 11 N+p

23. Three Body Model L. V. Grigorenko et al., Phys. Rev. Lett. 85 (2000) 22

24. Three-Body Decay Paths L. V. Grigorenko et al., Phys. Rev. Lett. 85 (2000) 22

25. Light Two-Proton Emitters

26. Two-Proton Decay of 6 Be g.s. 1.67 0.59 -1.37 4 He+2p 5 Li+p 6 Be (0 + ) (3/2 - ) (2 + ) D.F. Geesaman et al., Phys. Rev. C15 (1977) 1835

27. Transfer Reactions with Radioactive Beams

28. Production and Identification of short-lived Nuclei

29. Decay Energy Spectrum of 12 O  = 575 keV E Decay = 1.77 MeV

30. Two-Proton Angular Distribution Di-Proton Sequential

31. Decay Width Sequential Decay 12 O 11 N+p 10 C+p+p 12 O 10 C+2p 11 N+p However: Γ calc  10 keV Γ measured = 575 keV

32. Elastic Resonance Scattering L. Axelsson et al., Phys. Rev. C 54 (1996) R1511

33. Ground State of 11 N A. Azhari, et al. Phys. Rev. C57, 628 (1998) J. M. Oliviera, et al. Phys. Rev. Lett. 84, 628 (2000) K. Markenroth, et al. Phys. Rev. C62, 034308 (1998) 1.45 MeV 1.63 MeV 1.27 MeV 11 N

34. Two Proton Decay of 12 O Old New ?? 2.0 MeV 1.8 MeV ~1.5 MeV 12 O 11 N+p 10 C+2p

35. Di-Proton Decay of 16 Ne? L. V. Grigorenko et al., Phys. Rev. Lett. 88 (2002) 042502

36. New Shell Structure? Z=8 N=8 N=16 ? N=20 ??

37. Vanishing of the Proton Z=8 Shell ? 11 N (-1.92MeV) 7 B – 11 N – 15 F 5 Li – 9 B – 13 N – 17 F Z=8

38. Vanishing of the Proton Z=8 Shell ? 11 N (-1.27MeV) 15 F ??

39. Mass of 15 F ?? 11 N 15 F ??

40. Previous 15 F Measurement G. J. KeKelis et al., Phys. Rev. C 17, 1929 (1978) Binding Energy of 15 F : –1.47 MeV  = 1 MeV

41. Theoretical Prediction S. Grevy, O. Sorlin, and N. Vinh Mau, Phys. Rev. C56 (1997) 2885

42. Invariant Mass Measurements at GANIL 2% 87% 11%  Primary Beam: 24 Mg  Secondary Beams: 20 Mg, 18 Ne, 17 F  Fragments Energies: 35-43 MeV/nucleon  Stripping Reactions  Detectors: SPEG Spectrometer MUST array

43. 15 F  14 O + p T. Zerguerras et al., to be published Relative to KeKelis et al.  Binding Energy of 15 F : E gs = –1.00  0.08MeV  = 1.23  0.22MeV

44. Mass of 15 F !! 11 N 15 F !!

45. Two Proton Decay of 16 Ne Old New 1.5 MeV 1.4 MeV 1.0 MeV ?? 16 Ne 15 F+p 14 O+2p 15 F

46. Two Proton Decay of 19 Mg ??  Masses of 19 Mg and 18 Na are not known  Stripping reactions: 20 Mg  18 Na  17 Ne + p 20 Mg  19 Mg  17 Ne + 2p ~1.8 MeV ~1.2 MeV ?? 19 Mg 18 Na+p 17 F+2p Theoretical Predictions

47. First Measurement of the Mass of 18 Na  No events observed for 20 Mg  19 Mg  18 Na + 2p  Binding Energy of 18 Na : E gs = –0.411  0.05 MeV  = 0.34  0.09 MeV

48. Decay of 19 Mg Sequential ?? ~1.2 MeV 19 Mg 18 Na+p 17 F+2p 0.41 MeV  Two-Proton Decay will most likely be sequential.. .. unless the mass of 19 Mg is also underpredicted  Measure the mass of 19 Mg

49. Intermediate (1p) Nuclei

50. Two-Proton Decay of 14 O * 2 He Sequential 12 C+2p 13 N+p 14 O 6.57 0 4.63 2.37 3.51 7.77 6.59 5.17 9.72 1/2 + 3/2 + 2+2+ 0+0+ 0+0+ C.R. Bain et al., Phys. Lett. B373 (1996) 35

51. Level and Decay Scheme of 17 Ne

52.  -Decay of the First Excited State M. J. Chromik et al., Phys. Rev. C55 (1997) 1676

53. Experimental Setup

54. Decay Energy Spectrum of 17 Ne Counts

55. Experimental Setup 17 Ne Position sensitive detectors 15 Op Target 40x40 Silicon strip detector: Low gain: ==> 15 O position High Gain: ==> proton position 2x2 Silicon quadrant detector: 15 O energy loss 2x2 Silicon quadrant detector: 15 O energy 48 element CsI detector proton energy 40x40 Silicon strip detector proton position energy 2x2 Silicon quadrant detector: proton energy loss

56. Breakup Reactions in the Detectors can be identified using the new Setup 15 O,2p 17 Ne 15 O,2p 17 Ne Reaction in the Target Breakup in the First Pin  E in Pin1 [MeV] 17 Ne Penetrating the first Pin Breakup Pos. [m]

57. Coulomb Excitation of 17 Ne Decay Energy [keV] Number of Counts M. Chromik et al, to be published

58. 18 Ne  17 Ne *  15 O + 2p No evidence for 2p decay from the first excited state in 17 Ne

59. Two-Proton Decay of 18 Ne? J. Gomez del Campo et al., Phys. Rev. Lett. 86 (2001) 43

60. One and Two Proton Decay  1p = 50 keV  2p = 21-57 eV J. Gomez del Campo et al., Phys. Rev. Lett. 86 (2001) 43

61. Correlated or Uncorrelated? Relative EnergyOpening Angle J. Gomez del Campo et al., Phys. Rev. Lett. 86 (2001) 43

62. 2p and 3p Decay of 31 Ar 31 Cl 31 Ar 18.55 12.34  -decay 7.45 4.70 6.10 30 S+p 29 P+2p 28 Si+3p IAS 2p 3p D. Bazin et al., Phys. Rev. C45 (1992) 69 I. Mukha et al., Nucl. Phys. A630 (1998) 394c

63. Two-Proton Radioactivity W. E. Ormand, Phys. Rev. C53 (1996) 2145 W. E. Ormand, Phys. Rev. C55 (1997) 2407 B. A. Brown, Phys. Rev. C43 (1991) R1513 & 38 Ti(0.4-2.3)x10 -12 ms & 39 Ti0.4-2000 ms & 45 Fe10 -5 -10 -1 ms & 48 Ni0.01-3660 ms & 63 Se0.3-5000 ms

64. Decay Width and Lifetime Predictions L. V. Grigorenko et al., Phys. Rev. Lett. 85 (2000) 22

65. 45 Fe: 2-Proton Decay at GSI M. Pfützner et al., to be published

66. 45 Fe: 2-Proton Decay at GANIL J. Giovinazzo et al., to be published

67. 45 Fe: Di-Proton or Sequential? G. Audi and A.H. Wapstra, Nucl. Phys. A595 (1995) 409

68. Bridging the Waiting Points H. Schatz et al., Phys. Rep. 294 (1998) 167

69. Two-proton emitters and the (2p,  ) rates http://csep10.phys.utk.edu/astr162/lect/index.html

70. 17 Ne ( ,2p) 15 O 15 O+2p 16 F+p 17 Ne p p p 

71. 15 O(2p,  ) 17 Ne 15 O+2p 16 F+p 17 Ne p p p  QQ -Q z Q z+1

72. Does the (2p,  ) compete with the (  ) 4 8 12 16 20 0.20.40.60.81 Total Reaction Rate T (GK) Density [g/cm 3 ] Lines of equal rates:   p   p 

73. 20 Ne( 3 He, 6 He) 17 Ne V. Guimarães et al. Phys. Rev. C58 (1998) 116

74. New Level Scheme for 17 Ne V. Guimarães et al. Phys. Rev. C58 (1998) 116 5/2 _ _ 1/2 +

75. Modified Reactions Rates for 16 F(p,  ) Total Reaction Rate T (GK)

76. Does the (2p,  ) compete with the (  ) now? T (GK) Density [g/cm 3 ] Lines of equal rates:  p   p  

77. Use ( ,2p) to study (2p,  )  Final nucleus following (2p,  ) is particle stable  Use Coulomb dissociation ( ,2p) on stable nucleus & Potential waiting point candidates:  15 O(2p,  ) 17 Ne  18 Ne(2p,  ) 20 Mg  38 Ca(2p,  ) 40 Ti  64 Ge(2p,  ) 66 Se  68 Se(2p,  ) 70 Kr  72 Kr(2p,  ) 74 Y J. Görres, M. Wiescher, F.-K. Thielemann, Phys. Rev. C51, 392 (1995) F. Käppeler, F.-K. Thielemann, and M. Wiescher, Ann. Rev. Nucl. Part. Sci. 48, 175 (1998)

78. 68 Se(2p,  ) 70 Kr 68 Se+2p 69 Br+p 70 Kr p p p  High T (>2GK) : total =  (Z) + f(T)*exp(  Q)*  (Z+2) QQ -Q z Q z+1 Low T (<2GK) : total =  (Z) + g(T)*exp(-Q z )*  p  

79. Reduction of Stellar Lifetime H. Schatz et al., Phys. Rep. 294 (1998) 167

80. &Energies and decay properties of the Z (waiting point +2) nucleus:  Coulomb excitation: (  ) and ( ,2p) 70 Kr( ,2p) 68 Se &Mass of the unstable Z (waiting point +1) nucleus: ?Transfer reaction: 9 Be( 70 Br, 69 Br) 68 Se + p What is needed?

81. Beam Intensities 70 Kr( ,2p) 68 Se 70 Br 70 Kr 68 Se 9 Be( 70 Br, 69 Br) RIA: 8x10 7 /s 70 BrRIA: 4x10 4 /s 70 Kr CC : 7x10 5 /s 70 BrCC : 3x10 2 /s 70 Kr

82. Conclusions &Still no conclusive evidence for di-proton decay &Light nuclei: ?“Phase space wins”: If it can decay sequential, it will ?Ground-state di-proton decay very unlikely ?Lower ground-state energies measured for 11 N, 15 F and 18 Na ?Still unresolved problem of large width in 12 O ?Measure 19Mg !! &Heavier nuclei: ?First evidence for two-proton decay in 45 Fe ?Determine the proton correlations ?Measure the mass of 44 Mn ?Deformation, structure and mass measurements