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Launch 09, Heidelberg November 09 - 12 2009 The GSI anomaly: experimental status

Launch 09, Heidelberg November 09 - 12 2009 The GSI anomaly: experimental status Fritz Bosch, GSI Helmholtzzentrum Darmstadt. FRS - ESR Collaboration. F. Bosch, D. Boutin, C. Brandau, L. Chen, Ch. Dimopoulou, H. Essel, Th. Faestermann,

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Launch 09, Heidelberg November 09 - 12 2009 The GSI anomaly: experimental status

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  1. Launch 09, Heidelberg November 09 - 12 2009 The GSI anomaly: experimental status Fritz Bosch, GSI Helmholtzzentrum Darmstadt

  2. FRS - ESR Collaboration F. Bosch, D. Boutin, C. Brandau, L. Chen, Ch. Dimopoulou, H. Essel, Th. Faestermann, H. Geissel, E. Haettner, M. Hausmann, S. Hess, P. Kienle, Ch. Kozhuharov, R. Knöbel, J. Kurcewicz, S.A. Litvinov, Yu.A. Litvinov, L. Maier, M. Mazzocco, F. Montes, A. Musumarra, G. Münzenberg, C. Nociforo, F. Nolden, T.Ohtsubo, A. Ozawa, W.R. Plass, A. Prochazka, R. Reuschl, Ch. Scheidenberger, U. Spillmann, M. Steck, Th. Stöhlker, B. Sun, T. Suzuki, S. Torilov, H. Weick, M. Winkler, N. Winckler, D. Winters, T. Yamaguchi

  3. Outline 1. Detection technique of electron-capture (EC) decay of stored and cooled hydrogen (H)-like ions 2. Results of EC decay of H-like 140Pr and 142Pm ions 3. Status of data evaluation of EC decays of H-like 122I ions4. Conclusions and next steps

  4. 1 Detection technique of EC decay of H-like ions Storage Ring ESR Linear Accelerator UNILAC Fragment Separator FRS Heavy-Ion Synchrotron SIS Production target

  5. Production and Separation of Exotic Nuclei Highly-Charged Ions In-Flight separation Cocktail or mono-isotopic beams Hans Geißel

  6. 'Cooling': narrowing velocity, size and divergence enhancing phase space density Electron cooling: G. Budker, 1967 Novosibirsk momentum exchange with 'cold', collinear e- beam. The ions get the sharp velocity of the electrons, small size and divergence

  7. Schottky Mass-and Lifetime Spectrometry (SMS) Continuous digitizing and storage of raw data

  8. time SMS 4 particles with different m/q Yuri A. Litvinov MPIK / GSI

  9. Sin(w1) Sin(w2) w4 w3 w2 w1 Sin(w3) time Sin(w4) SMS Fast Fourier Transform

  10. Schottky frequency spectra Δαkl

  11. ESR: circumference ≈ 104 cm For 1000 stored ions, the mean distance amounts to about 10 cm At mean distances of about 10 cm and larger intra-beam-scatteringdisappeared "Phase transition" to a linear ion-chain M. Steck et al., PRL 77, 3803 (1996)

  12. Two-body beta decay: monochromatic ν, same q

  13. 2 Results of EC-decay of H-like 140Pr and 142Pm ions

  14. Stochastic (3.5 s) + continuous electron cooling D. Boutin

  15. Two-body beta decay

  16. Restriction onto 1...3 stored H-like parent ions Continuous observation Detection of ALL EC decays Delay between decay and "appearance" due to cooling Parent/daughter correlation Well-defined creation and decay time No third particle involved

  17. The observables in the GSI experiments 1. Mass MP and charge of parent ion 2. Mass MD of cooled daughter ion 3. Time ta of daughter appearance 4. Not observed: 140Pr: TR = 44 eV Delay: 900 (300) msec 142Pm: TR = 90 eV Delay: 1400 (400) msec from observed frequencies: →p transformed to n (hadronic vertex) → bound e- annihilated (leptonic vertex) → ν created at td as νeif LNC holds true

  18. Why we have to restrict onto 3 injected ions at maximum ? The variance of the amplitude gets larger than the step 3→4 ions Daughter Amplitude Amplitude Mother Evaluation of amplitude distributions corresponding to 1,2,3-particles Nicolas Winckler

  19. 140Pr all runs: 2650 EC decays from 7102 injections Yu.A. Litvinov et al., Phys. Lett. B 664 (2008) 162-168

  20. 142Pm: 2740 EC decays from 7011 injections

  21. 142Pm: zoom on the first 33 s after injection

  22. Synopsis (140Pr & 142Pm) • Mparent ω(1/s)lab Periodlab (s) Amplitude φ(rad) • 140 0.890(10) 7.06(8) 0.18(3) 0.4(4) • 142 0.885(27) 7.10(22) 0.23(4) - 1.6(4)

  23. Quantum Beats from the Hyperfine States? Coherent excitation of the 1s hyperfine states F = 1/2, F= 3/2Beat period T = h/ΔE; for ΔE ≈ 1 eV →T ≈ 10-15 s µ = +2.7812 µN (calc.) Decay can occur only from the F=1/2 (ground) state Periodic spin flip to "sterile" F=3/2 ?→λEC reduced

  24. Asymptotic energy and momentum conservation M + p12/2M + E1 = E M + p22/2M + E2 = E "Asymptotic" conservation of E, p E, p = 0 (c.m.) νe (mi, pi, Ei) M, pi2/2M ΔEν ≈ Δm2/2MP ≈ 3.1·10-16 eV Δpν ≈ - Δm2/2< Eν >≈ - 10 -11 eV m12 – m22 = Δm2 = 8 · 10-5 eV2 E1 – E2 = ΔEν p1 – p2 = Δpν if frequency ω in cos(ωt + φ) connected with ΔΕν/ ћ = Δm2/2Mp → period T of modulation should be proportional to Mp

  25. Decay scheme of 118Sb 8- isomer populated with 75% probability !

  26. 3 Status of data evaluation of EC decays of H-like 122I ions Experiment: 31.07.2008-18.08.2008

  27. Few (1..3) stored parents: 10 808 inj., 1150 EC decays

  28. Few(1...3) stored parent ions: ~ 1150 EC decays

  29. Few stored parent ions, FFT: f = 0.168 Hz, 1/f = 6 s

  30. Many parent ions (20...30): 5718 injections ~ 4450 EC-decays

  31. Problems of data analysis for many parent ions 1. No correlations, only onset of daughter trace measured 2. Erraneous assignments possible (delayed cooling) → several independent evaluations needed

  32. Background does not show any periodic modulations

  33. Agreement within 0.64s for firstdecay ≥ 90% for second and third decay ~ 65% low signal-to-noise ratio (signal ~ q2; q = 52) large variance of the amplitudes → restriction onto files with oneEC decay only at the expense of significantly reduced statistics

  34. files with many parents and 1 EC decay ~ 1850 decays

  35. files with many parents and 1 EC decay: ω = 1.04(1) s-1

  36. Synopsis • Mparent ωlab(1/s) Periodlab (s) Amplitude φ(rad) • [122 1.04(1) 6.05(7) 0.21(3) - 0.2(2)] • 140 0.89(1) 7.06(8) 0.18(3) 0.4(4) • 142 0.885(27) 7.10(22) 0.23(4) - 1.6(4)

  37. Status of the analysis of EC decay of H-like 122I 1. The data with few parent ions provide about 1150 EC decays which show a modulation with a period of T = 6 s and an amplitude A = 0.2. 2. The data with many parent ions presently show a reasonable agreement of independent analyses only for the subset of injections where exactly 1 EC decay occurs. This data provide 1850 ECdecays which show a modulation with a period of T =6 s and an amplitude A = 0.2.

  38. Next steps • New resonant Schottky pick-up under construction • operating at 240 MHz, Q = 2800 • To probe whether the modulations could be connected with the spin and/or the hyperfine structure of the H-like ions, the EC decay of He-like 142Pm will be investigated soon. • To probe whether the modulations are connected with the magnetic rigidity, experiments with the same ion type but at different velocityshould be performed.

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