1. New Instruments for Neutrino Relics and Mass CERN, 8 December 2008
Orbital Electron-Capture Decay
of Stored and Cooled Hydrogen-like Ions
in the Experimental Storage Ring, ESR
Christophor Kozhuharov, GSI Darmstadt
Outline:
Motivation
Production, separation, storage, cooling, and nondestructive detecting of highly-charged radioactive ions at the FRS-ESR complex
Two-body electron-capture decay of highly-charged ions.
Single-ion decay spectroscopy
Experimental results for EC of H-like 140Pr and 142Pm ions
Some hypotheses on the observed non-exponential decay

2. FRS/ESR Mass-and-Lifetime Collaboration
G. Audi, K. Beckert, P. Beller†, F. Bosch, D. Boutin, C. Brandau, Th. Bürvenich, L. Chen, I. Cullen, Ch. Dimopoulou, H. Essel, B. Fabian, Th. Faestermann, B. Franczak, B. Franzke, H. Geissel, E. Haettner, M. Hausmann, S. Hess, P. Kienle, O. Klepper, H.-J. Kluge, C. Kozhuharov,
R. Knöbel, J. Kurcewicz, S.A. Litvinov, Yu. A. Litvinov, Z. Liu, L. Maier, M. Mazzocco, F. Montes, A. Musumarra, G. Münzenberg, S. Nakajima, C. Nociforo, F. Nolden, Yu. N. Novikov, T. Ohtsubo, A. Ozawa, Z. Patyk, B. Pfeiffer, W. R. Plass, Z. Podolyak, M. Portillo, A. Prochazka, R. Reuschl, H. Schatz, Ch. Scheidenberger, M. Shindo, V. Shishkin, U. Spillmann, M. Steck, Th. Stöhlker, K. Sümmerer, B. Sun, K. Suzuki, K. Takahashi, S. Torilov, M. B. Trzhaskovskaya, S. Typel, D. J. Vieira, G. Vorobjev, P.M. Walker, H. Weick, S. Williams, M. Winkler, N. Winckler, D. Winters, H. Wollnik, T. Yamaguchi
8 December 2008
Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions

3. Bound-State β-Decay M. Jung et al. Phys. Rev. Lett. 69 (1992) 2164
8 December 2008
Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions

4. Two-body β-decay of highly-charged ions
8 December 2008
Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions

5. Secondary Beams of Short-Lived Nuclei
Storage
Ring
ESR
Linear
Accelerator
UNILAC
Fragment
Separator
FRS
Heavy-Ion
Synchrotron
SIS
Production
target
8 December 2008
Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions

6. Production & Separation of Exotic Nuclei
Highly-Charged Ions
In-Flight separation
Cocktail or one single nuclear species
≈ 600 MeV/u primary beams
400 MeV/u stored beams: fragments
e.c. 140Pr, 142Pm, 205Hg, 207Tl, 206Tl, 122I

7. Experimental Storage Ring, ESR: 108.4 m, 10-11 mbar
8 December 2008
Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions

8. Stochastic cooling at the ESR
Combiner Station
Long. Pick-up
Transv. Pick-up
Long. Kicker
Transv. Kicker
ESR storage ring
Stochastic cooling is particularly efficient for hot ion beams
(Fixed energy: 400 MeV/u)
8 December 2008
Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions

9. Electron cooling: G. Budker, 1967 Novosibirsk
Cooling, i.e. enhancing the phase space density at constant beam velocities
Electron cooling: G. Budker, 1967 Novosibirsk
The momentum exchange of the ions with the cold collinear e- beam leads to an excellent emittance
8 December 2008
Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions

10. 'Phase transition' to a linear ion chain
ESR circumference ≈ 104 cm
At mean distances of about 10 cm and larger
the intra-beam-scattering disappears.
For 1000 stored ions, the mean distance amounts to about 10 cm.
M. Steck et al.,
PRL 77, 3803 (1996)
8 December 2008
Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions

11. Recording the Schottky-noise
Real time analyzer Sony-Tektronix 3066
____________________________ 128 msec
→ FFT
64 msec_____________________

12. SMS
4 particles with different m/q
time

13. Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions
SMS
Sin(w1)
Sin(w2)
Sin(w3)
Sin(w4)
Fast Fourier Transform w1 w2 w3 w4
time
8 December 2008
Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions

14. 300 kHz / 60 MHz Schottky TCAP

15. Orbital EC-experiments, decay schemes
8 December 2008
Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions

16. Well-defined quantum states for parent and daughter ions
I Well-defined states:
→ bare, 1, 2.. e-
II Quasi 'free':
→ storage ring/ trap
III Time-resolved decay:
→ single ions
IV Correlated decay:
→ change of mass
8 December 2008
Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions

17. Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions
Cooling at ESR
David Boutin, PhD Thesis, Univ. Giessen, 2005
8 December 2008
Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions

18. Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions
Two-body beta decay
f scales as m/q
q does not change for the two-body β decay
f changes only if the mass changes, or if the B-field changes.
260 Hz
8 December 2008
Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions

19. EC in Hydrogen-like Ions
Expectations:
lb+/lEC (neutral atom) ≈ 1
lEC(H-like)/lEC(He-like) ≈ 0.5
FRS-ESR Experiment
l(neutral) = (1) s-1
G.Audi et al., NPA729 (2003) 3
lb+(bare) = (8) s-1 (decay of 140Pr59+)
lEC(H-like) = (6) s-1 (decay of 140Pr58+)
lEC(He-like) = (7) s-1 (decay of 140Pr57+)
lEC(H-like)/lEC(He-like) = 1.49(8)
Yu. A. Litvinov et al.,
PRL 99, (2007)
8 December 2008
Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions

20. Electron Capture in Hydrogen-like Ions
Gamow-Teller transition 1+  0+
S. Typel and L. Grigorenko
µ = µN (calc.)
Theory: Z. Patyk et al., PR C77, (2008)
The H-like ion decays
by 20% faster than the neutral atom!
Probability of EC Decay
Neutral 140Pr:
P = 2.381
He-like 140Pr:
P = 2
λ(H)/λ(He) = (2I+1)/(2F+1)
H-like 140Pr:
P = 3
8 December 2008
Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions

21. Nuclear Decay of Stored Single Ions
Time/channel = 30 sec.
8 December 2008
Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions

22. We restrict the analysis to 1 to 3 injected ions:
1. The Schottky areas have a very large variance.
2. The variance of the amplitudes is larger than the step 3→4.
3. Problem of 'delayed cooling'
Daughter
Amplitude
Amplitude
Mother
N. Winckler
Amplitude distributions corresponding to 1,2,3-particles; 1 frame = 128 msec.
The final data occur within msec. in both the computer as well as in the ‘manual’ evaluations; In all cases the ‘appearance’ time has been taken into account.

23. Examples of measured time-frequency traces
↕ Time/ch. = 640 msec
Time/ch. = 640 ms
8 December 2008
Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions

24. Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions
↕ Time/ch. = 64 msec
2 140Pr58+
1 140Pr58+
1 140Ce58+
8 December 2008
Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions

25. Properties of measured time↔frequency traces
1. Continuous observation
2. Parent/daughter correlation
3. Detection of all EC decays
4. Delay between decay and
"appearance" due to cooling
5. 140Pr: ER = 44 eV
Delay: 900 (300) msec
142Pm: ER = 90 eV
Delay: 1400 (400) msec
from measured frequency: → p transformed to n (hadronic vertex)
→ bound e- annihilated (leptonic vertex)
→ ν created at td as νe = a │ν1 > + b ν2 >
if conservation of lepton number holds
8 December 2008
Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions

26. 2. Experimental results for EC of H-like ions: 140Pr58+
8 December 2008
Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions

27. Fast Fourier Transform of the data of 1.+2. run
Frequency peak at f = Hz
Yu. A. Litvinov et al.,
Phys. Lett. B 664, 124 (2008)
8 December 2008
Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions

28. Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions
140Pr58+ all runs: 2650 EC-decays from 7102 injections
8 December 2008
Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions

29. Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions
142Pm60+: 2740 EC decays from 7011 injections
8 December 2008
Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions

30. Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions
142Pm60+: zoom on the first 33 s after injection
8 December 2008
Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions

31. Fits with pure exponential (1) and superimposed oscillation (2)
dNEC (t)/dt = N0 exp {- λt} λEC ; λ = λβ+ + λEC + λloss (1)
dNEC (t)/dt = N0 exp {- λt} λEC(t); λEC(t) = λEC [1+a cos(ωt+φ)] (2)
T = 7.06 (8) s
φ = 0.4 (4)
a = 0.18 (3)
T = 7.10 (22) s
φ = (4)
a = 0.23 (4)
8 December 2008
Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions

32. 3. Some hypotheses on the non-exponential decays
8 December 2008
Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions

33. EC in H-like ions for nuclear g.s. → g.s. transitions
Decay identified by correlated change of atomic mass at time td
Different delay due to emission characteristics of the neutrino
Small total line width(s)
Ћ / ΔtObs (≈ 0.1 s ) ≈ eV >> Ћ / T (≈ 7 s) ≈ eV
No third particle involved
→ daughter nucleus and neutrino entangled by momentum-
and energy conservation → EPR scenario
8 December 2008
Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions

34. Quantum beats from the hyperfine states ?
Coherent excitation of the 1s hyperfine states F =1/2 & F=3/ Beat period T = h/ΔE ≈ s
µ = µN (calc.)
Decay can occur only from the F=1/2 (ground) state
Periodic spin flip to "sterile" F=3/2 ? → λEC reduced
8 December 2008
Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions

35. Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions
"Classical" quantum beats
Coherent excitation of an electron in two quantum states, separated by ΔE at time t0, e.g. 3P0 and 3P2
Observation of the decay photon(s) as a function of (t-t0)
Exponential decay modulated by
cos(ΔE / Ћ (t-t0))
- Δτ -
if Δτ<< T = h/ΔE
→ no information whether E1 or E2
"which path"? addition of amplitudes
Chow et al., PR A11(1975) 1380
8 December 2008
Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions

36. Beats due to neutrino being not a mass eigenstate?
The electron neutrino appears as coherent superposition of mass eigenstates
The recoils appear as coherent superpositions of states entangled with the
electron neutrino mass eigenstates by momentum- and energy 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
m12 – m22 = Δ2m = 8 · 10-5 eV2
E1 – E2 = ΔEν
ΔEν ≈ Δ2m/2M = 3.1 · eV
Δpν ≈ - Δ2m/ 2 <pν> = 2.0 · eV
8 December 2008
Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions

37. Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions
cos (ΔE/ћ t) with Tlab = h γ / ΔE ≈ 7s
a) M = 140 amu, Eν = 3.39 MeV (Pr)
b) M = 142 amu, Eν = 4.87 MeV (Pm)
M =141 amu, γ = 1.43, Δ2m12 = 8 · 10-5 eV2
ΔE = hγ / Tlab = 8.4 · eV
ΔEν = Δ2m /2 M = 3.1 · eV
8 December 2008
Christophor Kozhuharov, GSI Darmstadt EC-Decay of H-Like Ions

38. New Experiment on 118Sb (122I)

39. Decay scheme of 118Sb
Experiment was scheduled:

40. Decay scheme of 122I

41. Correlations: 10.808 injections ~1080 EC-decays
Decay statistics
Correlations: injections ~1080 EC-decays
Many ions: 5718 injections ~5000 EC-decays
Analyzed :
I. About 60% of the overall data
II. About 20% of the overall data
Automatic analysis is delayed

42. For the two-body EC decays of H-like 140Pr and 142Pm periodic modulations according to e –λt [1+a cos(ωt+φ)] with Tlab = 2π/ω = 7s, a ≈ 0.20 (4) were found
Statistical fluctuations are not excluded on a c.l. > 3.5 σ
Oscillation period T proportional to nuclear mass M ?

43. Only a few out of many remaining questions
1. Are the oscillations real ? → still modest statistics
2. Can the coherence be maintained over some 10 s
keeping in mind the confinement in an electromagnetic potential, the continuous interaction, and the continuous observation ??
How can we improve the statistics, what other systems can we probe, what other ESR settings can we use?