2. 2

3. 3

4. 4

5. 5

6. 6

8. 8

9. 9 A s an example of probing such valence occupations, here is work done a long time ago. We measured (d,p) cross sections in the 4 even Zn isotopes to all accessible final states. Phys. Rev. 164, 1374 (1967)

10. 10

11. 11

12. 12 (e,e’p) from Lapikas et al.

13. 13

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17. 17

19. 19

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28. 28

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51. 51

52. 52 (e,e’p) results by Lapikas et al.

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66. 9

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70. 70 Comparison of ( 3 He,d) with ( ,t) for same transfer.

72. 72

73. 73

74. 74

75. 75 Yale Spectrograph

76. Triton spectra at 6 0 Colors: g 7/2 h 11/2

78. 78 * Using a single normalization for all 14 transitions. Target Ratio (  6  ) S 7/2 * S 11/2 * 112 Sn1.470.990.84 114 Sn1.391.100.93 116 Sn1.570.950.97 118 Sn1.640.880.99 120 Sn1.411.131.12 122 Sn1.450.981.00 124 Sn1.591.001.12

81. 81

84. 84 Similar trend in N=82 isotones There are 5 stable isotones (Sm, Nd, Ce, Ba, Xe) Fragmentation is known to be more significant than in Sn. Xe requires a gas cell Previous work done at Oxford in the 70’s Choose to explore the neutron-adding (α, 3 He) reaction.

85. 85 Considerable fragmentation seen (mostly one additional state) ! Centroid of single-particle strength shifts. Estimated uncertainty: Absolute cross sections ~7% Relative cross section <5% Relative spectroscopic factors ~10% Other fragments? Confident to limit of 5% of strongest

86. 86

87. 87

88. 88

89. 89 For Z=51 h 11/2 neutrons are filling in Sn REPULSIVE effect on πh 11/2. ATTRACTIVE effect on πg 7/2. Difference is~0.12 MeV per nucleon From (d,p) studies in the 1960's. Otsuka et al. [PRL95(2005)232502]

90. 90 Expectations for Z=51 GT2: Gogny + tensor D1S: traditional Gogny Quantitative measurements  -spectroscopy only ‘ultra’ neutron rich (for the far future) neutron rich Mean field calculations now explicitly include a tensor term The trend in stable isotopes should flatten above N=82 Start reversing above N=90 Otsuka et al. [PRL97(2006)232501]

91. 91 For N=83 From ( 3 He,d) work in 1960-s. πg 7/2 protons filling as Z increases (and N-Z decreases). ATTRACTIVE for i 13/2 REPULSIVE for h 9/2 ~0.18 MeV per nucleon

92. 92 Interpretation (N=82) From tensor matrix elements provided by Otsuka, uncertainty arises from proton occupancies

93. 93 Mean-field challenges The details of the filling of protons in the πg 7/2 and πd 5/2 orbitals matter. Recent HF calculations treated the filling of these orbits sequentially, and it does matter. G. Colo et al. Phys Lett. B 646(2007)227

94. 94

95. 95