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

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

Outline

Fragment Separator

FRS

1 Detection technique of EC decay of H-like ions

Productiontarget

StorageRingESR

Heavy-IonSynchrotron

SIS

LinearAccelerator

UNILAC

Production and Separation of Exotic Nuclei

Highly-Charged IonsIn-Flight separation

Cocktail or mono-isotopic beams

Hans Geißel

'Cooling': narrowing velocity, size and divergence enhancing phase space density

momentum exchangewith 'cold', collinear e- beam. The

ionsget the sharp velocity of the

electrons,small size and divergence

Electron cooling: G. Budker, 1967 Novosibirsk

Electron cooler

G as-target

Q uadrupole-trip let

Septum -m agnet

D ipole m agnet

Fast kickerm agnet

RF-Acceleratingcavity

Hexapole-m agnets

From the FR S

Extraction

To the S IS

Q uadrupole-dublet

Schottky p ick-ups

Schottky Mass-and Lifetime Spectrometry (SMS)

Continuous digitizing and storage of raw data

SchottkyP ick-ups

Stored ion beam

f ~ 2 M H z0

FFT

am plificationsum m ation

time

SMSSMS

4 particles with different m/q

Yuri A. Litvinov MPIK / GSI

Sin(1)

Sin(2)

Sin(3)

Sin(4)

1234time

Fast Fourier Transform

SMSSMS

0 1 0 . 0 2 0 . 0 3 0 . 0 4 0 . 0 5 0 . 0 6 0 . 0 7 0 . 0 8 0 . 00

5

1 0

8 0 . 0 9 0 . 0 1 0 0 . 0 1 1 0 . 0 1 2 0 . 0 1 3 0 . 0 1 4 0 . 0 1 5 0 . 0 1 6 0 . 0

1 6 0 . 0 1 7 0 . 0 1 8 0 . 0 1 9 0 . 0 2 0 0 . 0 2 1 0 . 0 2 2 0 . 0 2 3 0 . 0 2 4 0 . 0

240.0 250.0 260.0 270.0 280.0 290.0 300.0 310.0 320.0

know n m asses A q+X unknow n m asses

N um ber of channels 216

R ecord ing tim e 30 sec

188 78+Pt

0

5

10

0

5

10

0

5

10

Frequency / kHz

Inte

nsity

/ ar

b. u

nits

201 84+

194 81+Tl

182 76+Pt182 76+

182 76+

189 79+

Ir

O s

Po

Hg

189 79+Au

177 74+W

196 82+Bi

196 82+Pb

184 77+Pt

184 77+Ir198 83+Bi

191 80+Tl

191 80+Hg

194 81+Au

200 83+Bi

183 76+Ir

183 76+O s

195 81+Tl195 81+PbPb

188 78+ 178 74+Re

190 79+Au

197 82+Bi

197 82+Pb

185 77+Ir

185 77+Pt192 80+Tl

192 80+Hg

199 83+Bi187 78+Pt

187 78+Au

Pb

190 79+Hg

IrAu 181 75+

198 82+Pb

193 80+Tl

193 80+Hg

194 80+Tl194 80+

189 78+

Tl191 79+Hg

187 77+

199 82+ Pb

Hg

196 81+

204 84+

Pt

Pb

Pt Ir186 77+

Po

187 77+Au

BiPbPb

182 75+Ir

194 80+Hg 189 78+Au189 78+

201 83+Po

201 83+Bi184 76+

184 76+O s

191 79+Au

203 84+Po

186 77+Pt

186 77+Ir181 75+R e198 82+Bi

193 80+Pb199 82+

O s181 75+

200 82+Bi

195 80+Tl

197 81+Pb

197 81+Bi 192 79+Hg

192 79+Au

198 81+Bi

198 81+Pb193 79+Tl

193 79+Hg

188 77+Au 205 84+Po

200 82+Pb200 82+Po195 80+Pb

190 78+Hg

190 78+Au

185 76+Pt

202 83+Po

202 83+Bi 197 81+Tl198 81+Pb

188 77+Pt

A q+X

15

0m

,g

6

5+

Dy

150

65

+

Tb

143

6

2+

143

m,g

6

2+

Eu S

m

157

68+

Er

127

55+

Cs

157

6

8+T

m

173

7

5+

166

72

+1

66

72+

180

78

+P

t

Re

Hf

Ta

152

6

6+

152

6

6+

Ho

Dy

159

6

9+

159

6

9+

13

6

59+

Tm

Yb

Pr

W

164

71+

171

74

Lu

16

4

71+

Hf

14

5

6

3+

122

53+

Gd

I

175

7

6+

161

70

+

138

6

0+161

70

+

16

8

7

3+16

8

73+

Os

TaW

Yb

Nd

Lu

14

9

65+

Tb

156

68

+

156

6

8+

Er

Tm

154

67+

154

67+

HoEr

163

71+

147

64

+

14

7

6

4+

147

6

4+

Dy

Tb

Gd

Lu

165

72

+1

65

7

2+

17

2

7

5+

163

7

1+

170

74

+

Hf

TaRe

W

Hf

10000 20000 30000 40000 50000 60000 70000 80000 90000 100000

8

7

6

5

4

3

2

1

0

Frequency / H z

Inte

nsity

/ ar

b. u

nits

m ass know n m ass unknow n

Schottky frequency spectraSchottky frequency spectra

Δαkl

ESR: circumference ≈ 104 cm

At mean distances of about 10 cm and larger

intra-beam-scattering disappeared

For 1000 stored ions, the mean distance amounts to about 10 cm

"Phase transition" to a linear ion-chain

M. Steck et al., PRL 77, 3803 (1996)

Two-body beta decay: monochromatic ν, same q

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

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

Delay between decay and "appearance" due to

cooling

Parent/daughter correlation

Well-defined creation and decay time

No third particle involved

The observables in the GSI experiments

1. Mass MP and charge of parent ion

3. Time ta of daughter appearance4. 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

2. Mass MD of cooled daughter ion

Evaluation of amplitude distributions corresponding to 1,2,3-particles

Am

plit

ud

e

Am

plit

ud

e

Daughter

Mother

Why we have to restrict onto 3 injected ions at maximum ?

The variance of the amplitude gets larger than the step 3→4 ions

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 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)

µ = +2.7812 µN (calc.)

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

Decay can occur only from the F=1/2 (ground) state Periodic spin flip to "sterile" F=3/2 ? → λEC reduced

Quantum Beats from the Hyperfine States?

Asymptotic energy and momentum conservation

ΔEν ≈ Δm2/2MP ≈ 3.1·10-16 eV Δpν ≈ - Δm2/2< Eν > ≈ - 10 -

11 eV

E, p = 0 (c.m.)

M, pi2/2M

νe (mi, pi, Ei)M + p1

2/2M + E1 = E M + p2

2/2M + E2 = E"Asymptotic" conservation of E, p

m12 – m2

2 = Δm2 = 8 · 10-5

eV2

E1 – E2 = ΔEν

p1 – p2 = Δpνif 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 ≥ 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 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 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)

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 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 velocity should be

performed.