Transcript The GSI anomaly: experimental status Fritz Bosch, GSI Helmholtzzentrum Darmstadt

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,
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
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 ions
4. Conclusions and next steps
1 Detection technique of EC decay of H-like ions
Storage
Ring
ESR
Fragment
Separator
FRS
Production
target
Linear
Accelerator
UNILAC
Heavy-Ion
Synchrotron
SIS
Production and Separation of Exotic Nuclei
Highly-Charged Ions
In-Flight separation
Cocktail or mono-isotopic beams
Hans Geißel
'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
Schottky Mass-and Lifetime Spectrometry (SMS)
From the FRS
To the SIS
Quadrupoletriplet
Hexapolemagnets
Septummagnet
Dipole magnet
Schottky pick-ups
Gas-target
Electron
cooler
Schottky
Pick-ups
amplification
summation
FFT
Quadrupoledublet
f0 ~ 2 MHz
RF-Accelerating
cavity
Fast kicker
magnet
Stored ion beam
Continuous digitizing and storage of raw data
Extraction
SMS
4 particles with
different m/q
time
Yuri A. Litvinov MPIK / GSI
SMS
Sin(w1)
Sin(w2)
Fast Fourier Transform
time
Sin(w
3)
w4
Sin(w4)
w3
w2
w1
Schottky frequency spectra
10
74
197
195
W
200
193
185
Pt
mass unknown
Tl
83+
197
Bi 81+
50.0
193
Tl 81+
191
Au
Po 83+
201
78+
189
189
Hg 78+
Pt
Hg 79+
191
184
Ir
186
Au79+
186
Bi 83+
78+
198
184
76+
Os
76+
203
Pt
Ir
Po 84+
186
77+
193
77+
181
198
Bi
82+
181
Au77+
184
177
W
184
Pt 77+
Ir
181
Tl 80+
74+
0
0
10000 240.020000
30000
250.0
40000
260.0
X
71+
74+
Lu
W
known masses
unknown masses
160.0
81+
Tl
78+
201
163
182
Pb 81+
Tm68+
Dy
Tb 64+
147
Gd64+ 163 71+
Hf
156
220.0
Pt
76+
182
182
Po 84+
76+
Ir
Os76+
230.0
172
147
q+
q+
Pt
194
147
X
187
170
67+
Er
154
67+
Ho
Nd
60+
210.0
138
A
Os75+
Au 78+
Bi 83+
Hg 80+
150.0
64+
70+
Lu
161
I
122 53+
Gd63+
200.0
A
198
Yb
77+
Ir
70+
185
Tl 80+
161
Pt
77+
187
193
Re 75+
194
154
73+
W
Hg 80+
Hg 80+
Ir
Pb 80+
75+
140.0
199
192
185
145
191
192
Pb 82+
168
152
190.0
130.0
Bi 82+
Dy
Yb
77+
191
Au 79+
197
152
66+
69+
Re74+
Pr 59+ 159
Eu 62+
Sm62+
143
Bi 82+
178
180.0
Pb 82+
150m,g
196
76+
Dy
65+
Tb
180
65+
55+
196
Cs
Hg
79+
150
189
Au79+
Ir
170.0
127
189
Pt 78+
Er
157
Tm
0
160.0
10
183
Os 76+
136
183
72+
Pt
Ta
Au78+
68+
188
78+
166
188
175
190
5
197
66+
Pb 81+
Ho
Tl
76+
195
120.0
Δαkl
Hg 79+
81+
Os
190
Tm
Bi 83+
110.0
69+
100.0
Tl 80+
Pb 82+
72+
189
80.0
Hf
Hg 80+
70.0
165
196
60.0
240.0
65+
Tl 80+
75+
195
Hg 79+
Tb
165
72+
Ta
194
Lu
200
192
76+
16
149
194
40.0
80+
90.0
Au79+
81+
Re
30.0
159
80.0
10
5
202
197
173
0
1
mass knownPo
Hg 78+
Po 84+
201
Ir
190
Bi 83+
68+
77+
Pb 82+
195
Pb80+
202
Au78+
Er
75+
Pt
20.0
Re
182
187
68+
2
77+
157
3
Au
71+
4
187
205
Pb 82+
164
5
199
164
5
Bi
Pb
82+
Po 84+
Hf 71+
204
Au77+
200
Po 82+
168
166
194
199
143m,g
6
200
188
Tl 79+
Pt
192
190
156
10.0
0
Hg 79+
Bi 82+
75+
193
10
Intensity / arb. units
Intensity / arb. units
0
Bi
Pb 81+
72+
7
81+
Pb 81+
Tl 80+
73+
198
198
77+
Ta
5
188
Hf
171
8
Number of channels 2
Recording time 30 sec
Bi 83+
50000
270.0
280.0
60000
Frequency
/ kHz /
Frequency
Hz
290.0
70000
80000
300.0
310.0
320.0
100000
90000
"Phase transition" to a linear ion-chain
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-scattering disappeared
M. Steck et al.,
PRL 77, 3803 (1996)
Two-body beta decay: monochromatic ν, same q
2 Results of EC-decay of H-like
ions
140Pr
and 142Pm
Stochastic (3.5 s) + continuous electron cooling
D. Boutin
Two-body beta decay
Restriction onto 1...3 stored H-like parent ions
Continuous observation
Detection of ALL EC decays
Parent/daughter correlation
Delay between decay and
"appearance" due to cooling
Well-defined creation and decay time
No third particle involved
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 νe if LNC holds true
Why we have to restrict onto 3 injected ions at maximum ?
Amplitude
Amplitude
The variance of the amplitude gets larger than the step 3→4 ions
Daughter
Mother
Evaluation of amplitude distributions
corresponding to 1,2,3-particles
Nicolas Winckler
140Pr
all runs: 2650 EC decays from 7102 injections
Yu.A. Litvinov et al., Phys. Lett. B 664 (2008) 162-168
142Pm:
2740 EC decays from 7011 injections
142Pm:
zoom on the first 33 s after injection
Synopsis (140Pr & 142Pm)
Mparent ω(1/s)lab
φ(rad)
Periodlab (s) Amplitude
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)
Quantum Beats from the Hyperfine States?
Coherent excitation of the 1s hyperfine states F = 1/2, F= 3/2
Beat 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
Asymptotic energy and momentum
conservation
E, p = 0 (c.m.)
νe (mi, pi, Ei)
M + p12/2M + E1 = E
M + p22/2M + E2 = E
"Asymptotic" conservation of E, p
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
Decay scheme of 118Sb
8- isomer populated with 75% probability !
3 Status of data evaluation of EC decays of H-like 122I ions
Experiment: 31.07.2008-18.08.2008
Few (1..3) stored parents: 10 808 inj., 1150 EC decays
Few (1...3) stored parent ions: ~ 1150 EC decays
Few stored parent ions, FFT: f = 0.168 Hz, 1/f = 6 s
Many parent ions (20...30): 5718 injections ~ 4450 EC-decays
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
Background does not show any periodic modulations
Agreement within 0.64s for first decay
for second and third decay
≥ 90%
~ 65%
low signal-to-noise ratio (signal ~ q2; q = 52)
large variance of the amplitudes
→
restriction onto files with one EC decay only
at the expense of significantly reduced statistics
files with many parents and 1 EC decay ~ 1850 decays
files with many parents and 1 EC decay: ω = 1.04(1) s-1
Synopsis
Mparent
[122
ωlab(1/s)
1.04(1)
Periodlab (s)
6.05(7)
Amplitude
φ(rad)
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)
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 EC decays which show a modulation with
a period of T = 6 s and an amplitude A = 0.2.
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 Hlike 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 velocity should be performed.