1. Isospin impurity of the Isobaric Analogue State of super-allowed beta decay experimental technique isospin impurity determination Bertram Blank, CEN Bordeaux-Gradignan ESNT, Saclay, April, 26-29, 2011

2. The idea: T, T z - 1 T-3/2, T z -3/2 T, T z Super-allowed  decay Proton emission T - 1, T z - 1 Gamma decay

3. The idea: 52 Co: T=2, T z =-1 51 Fe: T=1/2, T z =-1/2 52 Ni: T=2, T z= -2 Super-allowed  decay Proton emission: T=1/2, T z = -1/2 T= ½ + ½ T = 1, T z = -1 T = 2 Gamma decay Can one determine the isospin impurity of the IAS?

4.  Calcium: 37,36 Ca  Titanium: 41,40,39 Ti  Vanadium: 43 V  Chromium: 45,44,43,42 Cr  Manganese : 47,46 Mn  Iron: 49,48,47,46,45 Fe  Cobalt: 51,50 Co  Nickel: 53,52,51,50,49,48 Ni  Copper: 55 Cu  Zinc: 56,55,54 Zn Proton-rich nuclei in the region of Ca to Ni Mass region (20  Z  28 et Tz  -3/2)  5 experiments at GANIL  23 isotopes studied ( 39 Ti au 53 Ni) Mass region (20  Z  28 et Tz  -3/2)  5 experiments at GANIL  23 isotopes studied ( 39 Ti au 53 Ni)

5. Primary beam: 58 Ni @ 75 MeV/A intensity: 3 - 4  Ae SISSI target: nat Ni 200 mg/cm 2 spectrometer LISE3 : degrader Be (50  m) Wien filter detection setup silicon telescope identification of implanted fragments DSSSD (X-Y): 2 x 16 x 3 mm - veto for light particles - residual energy, x-y position - energy loss - time of flight: micro-channel plate detectors RF cyclotron

6. Identification projectile fragments 7 to 8 identification parameters

7. Proton and gamma branching ratios and energies 41 Ti T B1B1 B2B2 A  41 Ti Radioactivity of 41 Ti Radioactivity of 49 Fe Correlation time Protons  41 Ti Contaminant from 49 Fe and 45 Cr

8. Background subtraction for  rays 49 Fe Before After Contaminants Decay of 49 Fe C. Dossat et al., NPA 792 (2007) 18

9. Spectroscopy of 52 Ni T 1/2 = (40.8 ± 0.2) ms P p = (31.4 ± 1.5) % E p = (2815 ± 23) keV I p = (0.9 ± 0.4) % E p = (1349 ± 10) keV I p = (9.4 ± 1.3) % E p = (1057 ± 11) keV I p = (2.9 ± 0.3) % C. Dossat et al., NPA 792 (2007) 18

10. Spectroscopy of 48 Fe T 1/2 = (40.8 ± 0.2) ms P p = (31.4 ± 1.5) % E p = (1013 ± 12) keV I p = (1.8 ± 0.3) % E p = (2000-3000) keV I p = (1.4 ± 0.5) % E p = (1500-1900) keV I p = (2.0 ± 0.4) % C. Dossat et al., NPA 792 (2007) 18

11. Isotop e Half-life (ms) Total proton branching ratio (%) Mass excess via IMME 37 Ca 181.7 ± 3.672.2(43)- 36 Ca 100.1 ± 2.351.2(10)- 41 Ti 82.6 ± 0.591.1 (6)-15.717(7) 40 Ti 52.4 ± 0.395.8 (13)-9.06(8) 39 Ti 28.5 ± 0.993.7(28)- 43 V 79.3 ± 2.4< 2.5- 45 Cr 60.9 ± 0.434.4 (8)-19.49 (3) 44 Cr 42.8 ± 0.814.0 (9)-13.64 (2) 43 Cr 21.1 ± 0.492.5 (28)-1.92(6) 42 Cr 13.3 ± 1.094.4(50)- 47 Mn 88.0 ± 1.3< 1.7- 46 Mn 36.2 ± 0.457.0 (8)-12.49 (3) 49 Fe 64.7 ± 0.356.7 (4)-24.67 (2) 48 Fe 45.3 ± 0.615.9 (6)-18.07 (5) 47 Fe 21.9 ± 0.288.4 (9)-7.08 (4) 46 Fe 13.0 ± 2.078.7 (38)0.76 (10) 51 Co 68.8 ± 1.9< 3.2- 50 Co 38.8 ± 0.270.5 (7)-17.59 (4) 53 Ni 55.2 ± 0.723.4 (10)-29.39 (4) 52 Ni 40.8 ± 0.231.4 (15)-22.64 (3) 51 Ni 23.8 ± 0.287.2 (8)-11.93 (7) 50 Ni 18.5 ± 1.286.7(39)-4.14 (3) 49 Ni 7.5 ± 1.083.4 (132)- 55 Cu 27.0 ± 8.015.0 (43)- 56 Zn 30.0 ± 1.786.9(49)- 55 Zn 19.8 ± 1.391.0(51)-

12.  Proton emission from the IAS is isospin forbidden  Comparison of, and of for IAS : 48 Fe : = 2.1 % - = 30% = 42 % 52 Ni : = 10 % - = 38% = 64 %  Determination of isospin impurities with these experimental data: (experimental, theory)  ’ p : Coulomb and centrifugal barrier penetration S p = 1 Isospin impurities X

13. Isospin impurity: example of 48 Fe  = 2.1 %  = 42 %  I I = 0.52 % Measured energies (keV) Predicted energies (keV) E IAS 3037 (10)2979 E  (IAS – 1 + ) 2631 (1)2458 E  (2 + - ground state) 313.0 (5)233 W.A. Richter, B.A. Brown IAS Shell model ( 48 Mn)

14. Isospin impurity: example of 52 Ni  = 10 %  = 64 %  I I = 19 % Measured energy (keV) Predicted energy (keV) E IAS 2931 (10)2796 Shell model ( 52 Co) IAS W.A. Richter, B.A. Brown

15.  neighboring nuclei: surprising…  however:  shell-model study : I I ( 36 Ca) = 0.4 %, I I ( 40 Ti) = 17.3 % (Theory Jyväskylä in sd shell)  similar treatment possible for many other nuclei: 45,44 Cr, 46 Mn, 49 Fe, 53,51 Ni…. I I ( 48 Fe) = 0.52 %, I I ( 52 Ni) = 19 % Isospin impurity of IAS B.A. Brown, N. Smirnova….