Time-modulation of electron-capture decay factor detected...
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Time-modulation of electron-capture decay factor detected at GSI, Darmstadt Byung Kyu Park Department of Physics University of California, Berkeley Physics 250 March 20, 2008 Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 1 / 19
Transcript of Time-modulation of electron-capture decay factor detected...
Time-modulation of electron-capture decay factordetected at GSI, Darmstadt
Byung Kyu Park
Department of PhysicsUniversity of California, Berkeley
Physics 250March 20, 2008
Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 1 / 19
Outline
1 The Experiment
2 Hypotheses
3 Neutrino Oscillation
4 Prospects
Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 2 / 19
The Facility
Gesellschaft für Schwerionenforschung, Darmstadt1
1http://www.gsi.de/Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 3 / 19
What they study
Decay schemes for neutral Pr-140 and Pm-142
Atomic charge state affects decay rates and branching ratio.
Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 4 / 19
Heavy-ion production and storage
For runs 1 and 2
Schematic layout of the facility with heavy-ion synchrotron SIS, thefragment separator FRS, and the storage-cooler ring ESR highlighted.2
2Yu. A. Litvinov et al., arXiv:nucl-ex/0509019Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 5 / 19
Heavy-ion production and storage
For runs 3 and 4
Revolution frequency of ions in storage is measured by Schottky massspectroscopy. This experiment is described in detail by Litvinov.3
3Yu. A. Litvinov et al., arXiv:0801.2079v1Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 6 / 19
Heavy-ion production and storage
Tabulated experimental parameters for all runs
run ion E(152Sm) L(9Be) #inj[MeV/u] [mg/cm2]
1 140Pr58+ 507.8 1032 4532 140Pr58+ 507.8 1032 8423 140Pr58+ 601.1 2513 58074 142Pm60+ 607.4 2513 7011
Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 7 / 19
Weak decay
Example signal
electron-capture: 140Pr58+ →140 Ce58+ + νe + KE, ∆f ≈ 300 Hz
β+ decay: 142Pm60+ →142 Nd59+ + e+ + νe + KE, ∆f ≈ −150 kHz
Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 8 / 19
Weak decay
Example signal
electron-capture: 140Pr58+ →140 Ce58+ + νe + KE, ∆f ≈ 300 Hz
β+ decay: 142Pm60+ →142 Nd59+ + e+ + νe + KE, ∆f ≈ −150 kHz
Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 8 / 19
Experimental result
with 140Pr58+
Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 9 / 19
Experimental result
with 140Pr58+
Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 9 / 19
Experimental result
with 140Pr58+
Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 9 / 19
Experimental result
with 140Pr58+
Exponential decay with a modulation at a period of ≈ 7 s.
Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 9 / 19
Experimental result
with 142Pm60+
Inset shows Fourier transform of the datashowing a peak at f = 0.14 Hz again.
Data with the sinusoidal fit for first 36seconds
Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 10 / 19
Experimental result
Fit parameters
Fit parameters of 140Pr dataEq. N0λEC λ a ω χ2/DoF1 34.9(18) 0.00138(10) - - 107.2/732 35.4(18) 0.00147(10) 0.18(3) 0.89(1) 67.18/70
Fit parameters of 142Pm dataEq. N0λEC λ a ω χ2/DoF1 46.8(40) 0.0240(42) - - 63.77/382 46.0(39) 0.0224(41) 0.23(4) 0.89(3) 31.82/35
Null hypothesis of pure exponential decay is excluded to 99%confidence level based on χ2 tests.
Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 11 / 19
Hypotheses: (1) technical artifact?
Procommon period of 7 s for140Pr58+ and 142Pm60+.
Conapparatus sensitive to singleionPr and Pm ions coast ondifferent orbits in ESRuncertainty of decay time(≈ 1 s) less than observedperiod.
Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 12 / 19
Hypotheses: (1) technical artifact?
Procommon period of 7 s for140Pr58+ and 142Pm60+.
Conapparatus sensitive to singleionPr and Pm ions coast ondifferent orbits in ESRuncertainty of decay time(≈ 1 s) less than observedperiod.
Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 12 / 19
Hypotheses: (2) quantum beat of hyperfine states
Pro140Pr and 142Pm have nuclearspin I = 1.H-like ions probably producedin coherent superposition oftwo 1s hyperfine states withF = 1/2 and F = 3/2.Final state (daughter ion plusνe) has F = 1/2.EC-decay from F = 3/2 stateis not allowed.
ConThe well-known hyperfinesplitting in hydrogen is inmicrowave range(ν = ∆E/h = 1420 MHz), withperiod of,
T = h/∆E = 0.7 ns,
and T for 140Pr58+ is evensmaller by a factor of ≈ 105.
Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 13 / 19
Hypotheses: (2) quantum beat of hyperfine states
Pro140Pr and 142Pm have nuclearspin I = 1.H-like ions probably producedin coherent superposition oftwo 1s hyperfine states withF = 1/2 and F = 3/2.Final state (daughter ion plusνe) has F = 1/2.EC-decay from F = 3/2 stateis not allowed.
ConThe well-known hyperfinesplitting in hydrogen is inmicrowave range(ν = ∆E/h = 1420 MHz), withperiod of,
T = h/∆E = 0.7 ns,
and T for 140Pr58+ is evensmaller by a factor of ≈ 105.
Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 13 / 19
Hypotheses: (3) neutrino oscillation
Suggestive kinematic considerationFor two mass eigenstates, m1 and m2,{
E1 + p21/2M = QEC
E2 + p22/2M = QEC
In approximation (E1 + E2)/2M � 1
∆E = E2 − E1 = (m22 −m2
1)/2M
From KamLAND data4, with M = 140 amu,
∆E ≈ 6× 10−16 eV, andT = h/E ≈ 7 s
4Phys. Rev. Lett. 94, 081801 (2005), ∆m2 ≈ 8× 10−5 eV2
Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 14 / 19
Hypotheses: (3) neutrino oscillation
Suggestive kinematic considerationFor two mass eigenstates, m1 and m2,{
E1 + p21/2M = QEC
E2 + p22/2M = QEC
In approximation (E1 + E2)/2M � 1
∆E = E2 − E1 = (m22 −m2
1)/2M
From KamLAND data4, with M = 140 amu,
∆E ≈ 6× 10−16 eV, andT = h/E ≈ 7 s
4Phys. Rev. Lett. 94, 081801 (2005), ∆m2 ≈ 8× 10−5 eV2
Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 14 / 19
Hypotheses: (3) neutrino oscillation
Suggestive kinematic considerationFor two mass eigenstates, m1 and m2,{
E1 + p21/2M = QEC
E2 + p22/2M = QEC
In approximation (E1 + E2)/2M � 1
∆E = E2 − E1 = (m22 −m2
1)/2M
From KamLAND data4, with M = 140 amu,
∆E ≈ 6× 10−16 eV, andT = h/E ≈ 7 s
4Phys. Rev. Lett. 94, 081801 (2005), ∆m2 ≈ 8× 10−5 eV2
Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 14 / 19
Hypotheses: (3) neutrino oscillation
Suggestive kinematic considerationFor two mass eigenstates, m1 and m2,{
E1 + p21/2M = QEC
E2 + p22/2M = QEC
In approximation (E1 + E2)/2M � 1
∆E = E2 − E1 = (m22 −m2
1)/2M
From KamLAND data4, with M = 140 amu,
∆E ≈ 6× 10−16 eV, andT = h/E ≈ 7 s
4Phys. Rev. Lett. 94, 081801 (2005), ∆m2 ≈ 8× 10−5 eV2
Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 14 / 19
Hypotheses: (3) neutrino oscillation
Suggestive kinematic considerationFor two mass eigenstates, m1 and m2,{
E1 + p21/2M = QEC
E2 + p22/2M = QEC
In approximation (E1 + E2)/2M � 1
∆E = E2 − E1 = (m22 −m2
1)/2M
From KamLAND data4, with M = 140 amu,
∆E ≈ 6× 10−16 eV, andT = h/E ≈ 7 s
4Phys. Rev. Lett. 94, 081801 (2005), ∆m2 ≈ 8× 10−5 eV2
Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 14 / 19
Neutrino oscillation, a brief introduction
Predicted in 1950s and 1960s by Bruno Pontecorvo, in analogywith a similar phenomenon in neutral kaons.5
flavor (e, µ, τ ) eigenstates: |να〉 =∑
i U∗αi |νi〉
mass (1, 2, 3) eigenstates: |νi〉 =∑
α Uαi |να〉
mixing matrix for two neutrinos: U =
(cos θ sin θ− sin θ cos θ
)
5http://en.wikipedia.org/wiki/Neutrino_oscillationByung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 15 / 19
Neutrino oscillation, a brief introduction
Predicted in 1950s and 1960s by Bruno Pontecorvo, in analogywith a similar phenomenon in neutral kaons.5
flavor (e, µ, τ ) eigenstates: |να〉 =∑
i U∗αi |νi〉
mass (1, 2, 3) eigenstates: |νi〉 =∑
α Uαi |να〉
mixing matrix for two neutrinos: U =
(cos θ sin θ− sin θ cos θ
)
5http://en.wikipedia.org/wiki/Neutrino_oscillationByung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 15 / 19
Neutrino oscillation, a brief introduction
Predicted in 1950s and 1960s by Bruno Pontecorvo, in analogywith a similar phenomenon in neutral kaons.5
flavor (e, µ, τ ) eigenstates: |να〉 =∑
i U∗αi |νi〉
mass (1, 2, 3) eigenstates: |νi〉 =∑
α Uαi |να〉
mixing matrix for two neutrinos: U =
(cos θ sin θ− sin θ cos θ
)
5http://en.wikipedia.org/wiki/Neutrino_oscillationByung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 15 / 19
Neutrino oscillation, a brief introduction
Predicted in 1950s and 1960s by Bruno Pontecorvo, in analogywith a similar phenomenon in neutral kaons.5
flavor (e, µ, τ ) eigenstates: |να〉 =∑
i U∗αi |νi〉
mass (1, 2, 3) eigenstates: |νi〉 =∑
α Uαi |να〉
mixing matrix for two neutrinos: U =
(cos θ sin θ− sin θ cos θ
)
5http://en.wikipedia.org/wiki/Neutrino_oscillationByung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 15 / 19
Neutrino oscillation, a brief introduction
Predicted in 1950s and 1960s by Bruno Pontecorvo, in analogywith a similar phenomenon in neutral kaons.5
flavor (e, µ, τ ) eigenstates: |να〉 =∑
i U∗αi |νi〉
mass (1, 2, 3) eigenstates: |νi〉 =∑
α Uαi |να〉
mixing matrix for two neutrinos: U =
(cos θ sin θ− sin θ cos θ
)
5http://en.wikipedia.org/wiki/Neutrino_oscillationByung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 15 / 19
Decay amplitude, coherent or incoherent sum?
According to Ivanov et al.,6 decay amplitude is given by,
A(t) =∑
k=1,2,3
Ak (t) =∑
k
∫ t
0dτ〈If , νk |HW (τ)|Ii〉.
Giunti7 argues that A(t) is an incoherent sum over different channels,because,
|νe〉 =∑
k
U∗ek |νk 〉,
and in the time-dependent perturbation theory,
|νe(t)〉 =
∑j
|Aj(t)|2−1/2∑
k
Ak (t)|νk 〉.
6Ivanov et al. arXiv:0801.2121v1, Eq. 3, simplified7Giunti, arXiv:0801.4639v2
Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 16 / 19
Decay amplitude, coherent or incoherent sum?
According to Ivanov et al.,6 decay amplitude is given by,
A(t) =∑
k=1,2,3
Ak (t) =∑
k
∫ t
0dτ〈If , νk |HW (τ)|Ii〉.
Giunti7 argues that A(t) is an incoherent sum over different channels,because,
|νe〉 =∑
k
U∗ek |νk 〉,
and in the time-dependent perturbation theory,
|νe(t)〉 =
∑j
|Aj(t)|2−1/2∑
k
Ak (t)|νk 〉.
6Ivanov et al. arXiv:0801.2121v1, Eq. 3, simplified7Giunti, arXiv:0801.4639v2
Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 16 / 19
Decay amplitude, coherent or incoherent sum?
According to Ivanov et al.,6 decay amplitude is given by,
A(t) =∑
k=1,2,3
Ak (t) =∑
k
∫ t
0dτ〈If , νk |HW (τ)|Ii〉.
Giunti7 argues that A(t) is an incoherent sum over different channels,because,
|νe〉 =∑
k
U∗ek |νk 〉,
and in the time-dependent perturbation theory,
|νe(t)〉 =
∑j
|Aj(t)|2−1/2∑
k
Ak (t)|νk 〉.
6Ivanov et al. arXiv:0801.2121v1, Eq. 3, simplified7Giunti, arXiv:0801.4639v2
Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 16 / 19
Analogy: double-slit interference
Lipkin8 asserts that coherence results from uncertainty relationship(localized ion, finite momentum uncertainty).
8Lipkin, arXiv:0801.1465v2Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 17 / 19
Analogy: double-slit interference
Lipkin8 asserts that coherence results from uncertainty relationship(localized ion, finite momentum uncertainty).
8Lipkin, arXiv:0801.1465v2Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 17 / 19
Analogy: double-slit interference
Lipkin8 asserts that coherence results from uncertainty relationship(localized ion, finite momentum uncertainty).
8Lipkin, arXiv:0801.1465v2Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 17 / 19
Analogy: double-slit interference
Lipkin8 asserts that coherence results from uncertainty relationship(localized ion, finite momentum uncertainty).
8Lipkin, arXiv:0801.1465v2Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 17 / 19
Prospects
Experimental verification“It is obvious that our findings must be corroborated by the studyof other two-body beta decays (EC and βb).”9
“A similar analysis can be applied to a K-capture experiment ...Here there are a number of initial states having different degreesof ionization. Interference can only occur between initial stateshaving the same degree of ionization. Otherwise the analysis isthe same.”10
New method for studying neutrino mixingIf the effect is real and realistic theoretical model can be set up,this is a new method to study neutrino oscillation without the needto directly detect neutrinos.
9Yu. A. Litvinov et al., arXiv:0801.2079v110Lipkin, arXiv:0801.1465v2Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 18 / 19
References
Litvinov, et al., “Observation of non-exponential orbital electroncapture decays of hydrogen-like 140Pr and 142Pm ions,”http://arxiv.org/abs/0801.2079v1
Ivanov, et al., “On the time-modulation of the K-shell electroncapture decay of H-like 140Pr58+ ions produced by neutrino-flavourmixing,” http://arxiv.org/abs/0801.2121v1Giunti, C., “Comment on the neutrino-mixing interpretation of theGSI time anomaly,” http://arxiv.org/abs/0801.4639v2(Note: this comment refers to arXiv:0801.1465v1.)Lipkin, H. J., “New method for studying neutrino mixing and massdifferences,” http://arxiv.org/abs/0801.1465v2
Byung Kyu Park (UC Berkeley) Time-modulation of EC decay Physics 250 March 20, 2008 19 / 19
