AN ANOMALOUS AN ANOMALOUS CURVATURE CURVATURE EXPERIMENTEXPERIMENT
Carol Y. ScarlettCarol Y. Scarlett
Brookhaven National Brookhaven National LaboratoryLaboratory
Apr. 27Apr. 27thth, 2006, 2006
CollaboratorsCollaborators
Russ BurnsRuss Burns Don LazarusDon Lazarus Carol ScarlettCarol Scarlett Yannis SemertzidisYannis Semertzidis Mike SivertzMike Sivertz
Experiments Experiments
Experiments with Polarized Laser Experiments with Polarized Laser Light inside a dipole magnetic Light inside a dipole magnetic field:field:
E840 at BNLE840 at BNL
PVLAS ItalyPVLAS Italy
Have seen an effect above the Have seen an effect above the predicted QED background.predicted QED background.
BNL E840BNL E840
1989 Search for Axions at BNL 1989 Search for Axions at BNL E840 saw a rotation of polarized E840 saw a rotation of polarized light of light of order 10order 10-8-8 rad rad
Experiment used two CBA Dipole Experiment used two CBA Dipole magnets with B magnets with B 5.0 T and an 5.0 T and an optical cavity giving a length of optical cavity giving a length of 10 km… QED predicted rotation:10 km… QED predicted rotation:
5.8 5.8 · · 1010-12-12 rad rad
PVLASPVLAS
PVLAS has performed a similar PVLAS has performed a similar experiment to E840 with: B experiment to E840 with: B 5.5 5.5 T and an effective length T and an effective length 52 km 52 km
PVLAS Results (2005): both an PVLAS Results (2005): both an observed dichroism and ellipticity observed dichroism and ellipticity ~ 10~ 10-7-7 rad giving: m rad giving: maa ~ 1meV ~ 1meV
PVLAS plans for regeneration PVLAS plans for regeneration experimentexperiment
Axion Detection Exp.Axion Detection Exp.
Ellipticity changes: BNL E840 & PVLAS Ellipticity changes: BNL E840 & PVLAS
Optical EffectsOptical Effects
Ellipticity:Ellipticity:
Optical EffectsOptical Effects
Dichroism:Dichroism:
Photon-EM InteractionPhoton-EM Interaction
In the presence of an externally In the presence of an externally applied Magnetic field:applied Magnetic field:
1 A1 A
L= L= —— (E—— (E22+B+B22) + —— [(E) + —— [(E2 2 - B- B22))22 + 7 ( E + 7 ( E · · B )B )22]]
8 4 8 4 ππ
Vacuum becomes birefringentVacuum becomes birefringent
Photon-EM Photon-EM InteractionsInteractions A photon propagating through an A photon propagating through an
external field will acquire an external field will acquire an ellipticity:ellipticity:
nn|||| == 1 + 7 A B1 + 7 A B22ext ext sinsin22
nn = 1 + 4 A B = 1 + 4 A B22ext ext sinsin22
L L ππ LL
= = —— (n—— (n|||| - n - n ) = —— 3 A B ) = —— 3 A B22ext ext
Photon-EM InteractionPhoton-EM Interaction
Another type of ‘photon-photon’ Another type of ‘photon-photon’ scattering: axion intermediate statescattering: axion intermediate state
Theory of AxionsTheory of Axions
QCD Lagrangian contains CP QCD Lagrangian contains CP violating term, however strong violating term, however strong interactions conserve the CP interactions conserve the CP symmetry symmetry
Peccei & Quinn proposed axion fieldPeccei & Quinn proposed axion field QCD Ground State reinterpreted asQCD Ground State reinterpreted as
a dynamical variablea dynamical variable
a(x) / fa(x) / faa
Axion Field EquationAxion Field Equation
If we include the axion field in the Lagrangian If we include the axion field in the Lagrangian for photon-EM interactionsfor photon-EM interactions
L = (1/4) FL = (1/4) F F F + (1/2) ( + (1/2) (a a a –a –
~~
mm22aaaa22) + (1/4M) F) + (1/4M) F F F a + a +
((22/90m/90m44ee) [ (F) [ (F F F ) )22 + +
~~
(7/4) (F(7/4) (F F F ) )2 2 ]]
Axion Mass RangeAxion Mass Range
Experimental SetupExperimental Setup
Current experiment uses a RHIC QuadCurrent experiment uses a RHIC Quad
Experimental Experimental ParametersParameters Vacuum 10Vacuum 10-9 -9 TorrTorr Gradient 95 T/mGradient 95 T/m Quadrupole Field (Superconducting Quadrupole Field (Superconducting
Quad)Quad) HeNe laser at 543 nmHeNe laser at 543 nm Beam Diameter Beam Diameter ~~ 1.5 mm 1.5 mm Field Modulation: 80 mHz & 225 Field Modulation: 80 mHz & 225
mHzmHz
Experimental Experimental CalibrationCalibration Minimal calibration neededMinimal calibration needed No cavity mirror alignmentNo cavity mirror alignment No movement of mirrors in fringe No movement of mirrors in fringe
fieldsfields No residual gas due to cooling of No residual gas due to cooling of
magnetmagnet
Current StatusCurrent Status
Run 1 completed as of 10/30/2005: Run 1 completed as of 10/30/2005: ~6950 min of data taken ~6950 min of data taken
Run 2 completed as of 03/20/2006:Run 2 completed as of 03/20/2006:
~2088 min of useful data~2088 min of useful data Data analysis underwayData analysis underway Shunt measurement taken for Run Shunt measurement taken for Run
2 only2 only
Wk 1 DataWk 1 Data
Wk 1: Run 3 Normalized X-Position
0123
4567
0.01
0.07
0.13
0.19
0.25
0.31
0.37
0.43
0.49
Freq
Am
p
Series1
Wk 1: Run 3 Normalized Y-Position
0
2
4
6
8
10
12
0.01
0.07
0.13
0.19
0.25
0.31
0.37
0.43
0.49
Freq
Am
p
Series1
Small Signal AnalysisSmall Signal Analysis
In place of performing an FFT on the In place of performing an FFT on the normalized values of position ( i.e. normalized values of position ( i.e. position/total energy) can perform position/total energy) can perform an FFT on these variables an FFT on these variables separately…separately…
Can also use the FFT to look for Can also use the FFT to look for small signals in the derivative small signals in the derivative ( point-to-point change in a value) of ( point-to-point change in a value) of the available variables…the available variables…
FFT Change in PositionFFT Change in Position
Run 3 Data: FFT of Del Hor Position
0
0.05
0.1
0.15
0.2
0.25
0.3
0
0.0733165
0.146633
0.2199494
0.293266
0.3665826
0.4398989
Freq
Am
p
Series1
Run 3 Data: FFT of Del Ver Position
0.52
0.54
0.56
0.58
0.6
0.62
0.64
00.06
0.12
0.18
0.24 0.3
0.36
0.42
0.48
Freq
Amp Series1
FFT Total Energy FFT Total Energy (Sum)(Sum)
Wk 1 Run 3 FFT Total Energy (Sum)
0
2
4
6
8
100.01
0.07
0.13
0.19
0.25
0.31
0.37
0.43
0.49
Freq
Am
p
Series1
FFT Change in SumFFT Change in Sum
Run 3 Data: FFT of the Change in the Sum
1.212
1.214
1.216
1.218
1.22
1.222
1.224
1.226
1.2280
0.07
0.15
0.22
0.29
0.37
0.44
Freq
Am
p
Series1
Observations: 80 mHzObservations: 80 mHz
Run sets 2, 3, and 4 FFT of Sum
3.32
3.325
3.33
3.335
3.34
3.345
3.35
3.3550
0.05
0.09
0.14
0.19
0.23
0.28
0.33
0.37
0.42
0.47
Freq
Am
p
Series1
Observation: 225 mHzObservation: 225 mHz
Run Set 6 Data
0.00836
0.00837
0.00838
0.00839
0.0084
0.00841
0.00842
0.00843
0.00844
0
0.06
0.12
0.18
0.24
0.3
0.36
0.42
0.48
Freq
Am
p
Series1
Why Signal Drops?Why Signal Drops?
When taking an FFT of the change When taking an FFT of the change in a variable, where a small signal is in a variable, where a small signal is present, the phase of the signal present, the phase of the signal determines its amplitude and sign…determines its amplitude and sign…
Since the phase of the signal is Since the phase of the signal is unavailable, the initial phase is set unavailable, the initial phase is set by triggering on when the phase of by triggering on when the phase of the current is zero… the current is zero…
Adjusting PhaseAdjusting Phase
Adding I/50k with Phase: Zero (bl), Pi/6 (pk), Pi/3 (yl) and Pi/2 (gr)
0.424
0.426
0.428
0.43
0.432
0.434
0.436
0.438
1 8 15 22 29 36 43 50 57 64 71
Freq
Am
p
Series1
Series2
Series3
Series4
Adding I/50k with Phase: 2Pi/3 (bl), 5Pi/6 (pk) and Pi (yl)
0.38
0.39
0.4
0.41
0.42
0.43
0.44
0.45
1 8 15 22 29 36 43 50 57 64 71
Freq
Am
p Series1
Series2
Series3
Wk 2 Data:Wk 2 Data:
Goal for second run period was to Goal for second run period was to perform systematic studies:perform systematic studies:
Shunt MeasurementShunt Measurement
No Light MeasurementNo Light Measurement
Probing Alternative Probing Alternative PositionsPositions
in the Fieldin the Field
Measure the stray fieldMeasure the stray field
Wk 2: Data Wk 2: Data
Wk 2: Run 34 Data
0.01222
0.01224
0.01226
0.01228
0.0123
0.01232
0.01234
0.01236
0
0.04
0.08
0.12
0.16
0.2
0.24
0.28
0.32
Freq
Am
p
Series1
Peak observed at 80 mHzPeak observed at 80 mHz The amplitude of the peak: 6.43The amplitude of the peak: 6.431010-5-5 ± 1.01± 1.011010-5 -5 (stat)(stat)
Wk 2: DataWk 2: Data
Wk 2 Data: No Phase Shift (bl), +Pi/4 (pk), +Pi/2 (yl), +3Pi/4 (gr) and +Pi (pr)
0.0122
0.01225
0.0123
0.01235
0.0124
0.012450
0.05
0.09
0.14
0.19
0.23
0.28
0.33
Freq
Am
p
Series1
Series2
Series3
Series4
Series5
Possible BackgroundsPossible Backgrounds
Movement due to eddy currentsMovement due to eddy currents Electronic loopsElectronic loops Magnet Vibrations: test bench Magnet Vibrations: test bench
uses airbags to isolate magnetuses airbags to isolate magnet Temperature changes in test areaTemperature changes in test area Movement along surface of Movement along surface of
optical elementsoptical elements
External Magnetic External Magnetic FieldField
Work Bench: 0.7-0.8 Gauss
Magnet Center: 0.4-0.9 Gauss
Bellows: 0.8-1.0 Gauss
PR1: 0.0-5.9 Gauss
Observation: No LightObservation: No Light
Wk2: No Light Meas.
0
0.00002
0.00004
0.00006
0.00008
0.0001
0.00012
0.00014
0.00016
0
0.04
0.08
0.12
0.16
0.2
0.24
0.28
0.32
Freq
Am
p
Series1
No peak seenNo peak seen Amplitude at 80 mHz: 3.58Amplitude at 80 mHz: 3.581010-5-5 ± 3.40± 3.401010-5 -5 (stat)(stat)
Observations: ShuntObservations: Shunt
Wk 2: Shunt Meas.
0.00476
0.00478
0.0048
0.00482
0.00484
0.00486
0
0.05
0.09
0.14
0.19
0.23
0.28
0.33
Freq
Am
p
Series1
Peak seen at 80 mHzPeak seen at 80 mHz The extracted amplitude: 2.64The extracted amplitude: 2.641010-5-5 ± 6.82± 6.821010-6 -6 (stat)(stat)
Shunt: Phase ShiftShunt: Phase Shift
Wk 2 Shunt: No Phase Shift (bl), +Pi/4 (pk) and +Pi/2 (yl)
0.00476
0.00478
0.0048
0.00482
0.00484
0.00486
0
0.05
0.09
0.14
0.19
0.23
0.28
0.33
Freq
Am
p
Series1
Series2
Series3
DATA AT 225 – SUM DATA AT 225 – SUM
Data 225mHz
0.013320.013330.013340.013350.013360.013370.013380.013390.01340.013410.01342
Freq
Am
p
Series1
Peak observed at 225 mHzPeak observed at 225 mHz The amplitude of the peak: 3.76The amplitude of the peak: 3.761010-5-5 ± 1.03± 1.031010-5 -5 (stat)(stat)
DATA AT 225DATA AT 225
Data r29 225mHz: No shift (bl), +Pi/8 (pk), +Pi/4(yl) and +Pi/2
0.01330.013320.013340.013360.013380.01340.013420.01344
Freq
Am
p
Series1
Series2
Series3
Series4
Data rotated up to Pi/2Data rotated up to Pi/2 Amp Vary: (2.90 to 4.74)Amp Vary: (2.90 to 4.74)1010-5-5 ± (0.91 to 1.09)± (0.91 to 1.09)1010-5 -5 (stat)(stat)
SHUNT AT 225 - SUMSHUNT AT 225 - SUM
Shunt Data for r27 taken at 225mHz
0.00474
0.00476
0.00478
0.0048
0.00482
0.00484
0.00486
0.00488
0
0.04
0.09
0.13
0.18
0.22
0.27
0.31
0.36
0.4
0.45
0.49
Freq
Am
p
Series1
NO PEAK observed at 225 mHz in the shunt measNO PEAK observed at 225 mHz in the shunt meas The amplitude of 225mHz: 1.48The amplitude of 225mHz: 1.481010-5-5 ± 1.49± 1.491010-5 -5 (stat)(stat)
SHUNT AT 225SHUNT AT 225
Shunt r27: No shift (bl), +Pi/8 (pk), +Pi/4 (yl) and +Pi/2 (gr)
0.00474
0.00476
0.00478
0.0048
0.00482
0.00484
0.00486
0.00488
0
0.04
0.09
0.13
0.18
0.22
0.27
0.31
0.36
0.4
0.45
0.49
Freq
Am
p
Series1
Series2
Series3
Series4
Data rotated up to Pi/2Data rotated up to Pi/2 Amp Vary: (1.32 to 1.48)Amp Vary: (1.32 to 1.48)1010-5-5 ± (1.47 to 1.49)± (1.47 to 1.49)1010-5 -5 (stat)(stat)
Horizontal MovementHorizontal Movement
Wk 2 Data: Horizontal Movement
0
0.01
0.02
0.03
0.04
0.05
0.01
0.05
0.09
0.13
0.17
0.21
0.25
0.29
0.33
Freq
Amp Series1
Wk 2 Data: Change in Horizontal Position
0
0.0005
0.001
0.0015
0.002
0.0025
0.003
0
0.05
0.09
0.14
0.19
0.23
0.28
0.33
Freq
Amp Series1
No peak evident in either the FFT of the No peak evident in either the FFT of the horizontal position nor the FFT of its change…horizontal position nor the FFT of its change…
Vertical MovementVertical Movement
Wk 2 Data: Vertical Movement
0
0.02
0.04
0.06
0.08
0.1
00.04
0.08
0.12
0.16 0.2
0.24
0.28
0.32
Freq
Amp Series1
Wk 2 Data: Change in Vertical Movement
00.00050.0010.00150.0020.00250.0030.00350.004
0
0.05
0.09
0.14
0.19
0.23
0.28
0.33
FreqAm
p Series1
No peak evident in either the FFT of the vertical No peak evident in either the FFT of the vertical position nor the FFT of its change…position nor the FFT of its change…
E-Loop ScalingE-Loop Scaling
Wk 2: Run 32 No Light Meas. with Observed E-Loop
0
0.0001
0.0002
0.0003
0.0004
0.0005
0
0.05
0.09
0.14
0.19
0.23
0.28
0.33
Freq
Am
p Series1
E-Loop peaks observedE-Loop peaks observed A(Shunt): 2.05A(Shunt): 2.051010-4-4 ± 5.87± 5.871010-6 -6 (stat) (stat) A(NL): A(NL): 2.582.581010-4-4 ± 4.57± 4.571010-6 -6 (stat) (stat)
Wk 2: Run 33 E-Loop Observed in Shunt
0.00270.00280.00290.0030.00310.00320.00330.00340.00350.0036
0
0.05
0.09
0.14
0.19
0.23
0.28
0.33
Freq
Am
p Series1
E-Loop ScalingE-Loop Scaling
Wk 2 Data with Observed E-Loop
0.012
0.01205
0.0121
0.01215
0.0122
0.01225
0
0.05
0.09
0.14
0.19
0.23
0.28
0.33
Freq
Am
p Series1
E-Loop Data A(Shunt): 9.04E-Loop Data A(Shunt): 9.041010-5-5 ± 1.90± 1.901010-5 -5 (stat) (stat) Rescaling No Light gives peak ~ 20 times that in ShuntRescaling No Light gives peak ~ 20 times that in Shunt
Wk 2: Shunt Run 32 (blue) and Scaled up No Light (pink)
00.0020.0040.0060.0080.01
Freq
Amp Series1
Series2
Future Future
Repeat measurement with beam Repeat measurement with beam splitter to simultaneously observe splitter to simultaneously observe laser output…laser output…
Take longer data run periods to Take longer data run periods to improve statistics…improve statistics…
Develop a mirror cavity to search Develop a mirror cavity to search for agreement with E840/PVLASfor agreement with E840/PVLAS
ReferencesReferences
1.1. Peccei & Quinn, PRL 38 (1977), 1440 Peccei & Quinn, PRL 38 (1977), 1440 2.2. Wilczek, PRL 40 (1978), 279Wilczek, PRL 40 (1978), 2793.3. A Simple Solution to the Strong CP Problem with a Harmless A Simple Solution to the Strong CP Problem with a Harmless
Axion, Dine, Fischler and Srednicki, Phy. Lett. 104B, 199Axion, Dine, Fischler and Srednicki, Phy. Lett. 104B, 1994.4. CAST: A search for solar axions at CERN hep-ex/0304024CAST: A search for solar axions at CERN hep-ex/03040245.5. PVLAS Results INFN-LNL (REP) 206/05PVLAS Results INFN-LNL (REP) 206/056.6. ‘An Experiment to Search for Axions’ ‘An Experiment to Search for Axions’
www-phys.llnl.gov/N_Div/Axion/axion.htmlwww-phys.llnl.gov/N_Div/Axion/axion.html7.7. Axions, G. Raffelt, Space Science Reviews 100: 153-158, Axions, G. Raffelt, Space Science Reviews 100: 153-158,
200220028.8. Anomalous axion interactions and topological currents in Anomalous axion interactions and topological currents in
dense matter, M. Metlitski & A Zhitnitsky, Phy. Rev. D 72, dense matter, M. Metlitski & A Zhitnitsky, Phy. Rev. D 72, 045011 (2005)045011 (2005)
9.9. MINOWA Group, Solar axion search experiment with a MINOWA Group, Solar axion search experiment with a superconducting magnet, superconducting magnet, www-icepp.s.u-tokyo.ac.jp/~minowa/Minowa_Group.files/s…www-icepp.s.u-tokyo.ac.jp/~minowa/Minowa_Group.files/s…
Axion MassAxion Mass
10-10 10-5 1 eV 105
ma
Lab Exp
RG (DFSZ)
RG (Hadronic)
SN 87A
Relic Decays
a (Davis) > ]
a > ]
