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Search for Permanent Electric Dipole Moments of Francium Atom
Yasuhiro SAKEMI Research Center for Nuclear Physics (RCNP), Osaka University
For EDM collaboration at RCNP
K.Hatanaka, A.Tamii, S.Morinobu, Y.Shimizu, K.Fujita, Y.Tameshige, H.Matsubara,T.Kaneda (RCNP)K.Imai, Y.Takahashi, T.Murakami (Kyoto Univ.)
T.Wakasa (Kyushu Univ.), Bhanau P. Das (Indian Institute of Astrophysics)
Physics motivation
EDM experiment
Present status of Fr EDM search at RCNP
Summary
Electron EDM search
Francium atom
Fundamental interaction
Search for permanent EDM
CPT ~ invariant in quantum field theory : No evidence of violationT: Time Reversal ~ No evidence of violation CP: violation was found ~ K0, B decayCPT theorem + CP violation → T violation ?
Window to look at Beyond the Standard Model ~ Supersymmetry …
Time Reversal Symmetry ~ Violation ? ~ Test !
+-
+-
Td
s
EDM and MSSM
2
sin~
Mµθ
Electron EDM in MSSM → limit to SUSY particle mass and CP-violating phase
M=500 GeV case
Phase pattern ~ limit the SUSY particle mass
Dominant diagram
dn=Δu・du+Δd・dd+Δs・ds
Origin of EDMsT
heor
y
Experiments H
igh
ener
gy
Nuc
lear
A
tom
ic
Fundamental model ~ Supersymmetry, ….
QuarkEDM
QCD
Nucleonn
dn=Δu・du+Δd・dd+Δs・ds
Nuclear Atomic
QCD
Atomic theory
Nuclear theory
DiamagneticAtoms
Hg,Xe,Rn
Schiff Mom.
Z2(RN/RA)3
Molecular
Atomic theory
MoleculesPbO,YbF,TlF
Emol
Atomic theory
ParamagneticAtoms
Tl,Ce,FrZ3α2
QuarkChromo-EDM
ElectronEDM
Electric Dipole Moment
de(Standard Model)<10-37
Status of EDM experiments
Current limit e-EDM : |de|<1.5×10-27
from E.D.Commins ,205Tl
A challenge is set ! de < 10-28 e・cm
if EDM is observed~ Beyond the Standard Model
if EDM is measured~ signal of supersymmetry …~ mechanism of SUSY violation
Particle
Exp. Limit [10-27 e cm]
SM [factor to go]
Possible New Physics [factor to go]
e (Tl) < 1.6 1011 ≤ 1 µ < 1.05 *109 108 ≤ 200 τ < 3.1 * 1011 107 ≤ 1700 n < 63 104 ≤ 60 Tl (odd p) < 105 107 ≤ 105 Hg (odd n) < 0.21 105 various
EDM limits
EDM Measurement and Sensitivity
TNEKehd
⋅⋅⋅⋅⋅=
τδ 111
2
EdhEdBhEdBh
⋅=∆⇒
⋅−⋅=
⋅+⋅=
↑↓
↑↑
42222
νµνµν
E E
Sensitivity :
K: Enhancement factor ~ Atom EDM = Largest ~ FranciumE : Electric Field ~ Strong, 100 kV/cm = Laser trap in high vacuumN : Number of Particles ~ Many particles ! = Ion Source + Atom coolingτ: Coherence Time (Stored time) ~ Long ! = Laser trapT : Lifetime of Experimentalist ~ Long !
Electric dipole moment : d
System containing EDM
K×de
Amplified !
20
252
23
)0(~
~~
aeVZ
Zd
dK
s
e
atom
αψ
α
Why Francium traps ?
Heavy atoms amplify EDM ~ P.G.H. Sandars, Oxford, 1960sEnhancement factor:
Enhancement factor
0
200
400
600
800
1000
1200
1400
0 20 40 60 80 100
K
Char
ge :
Z
Enhancement factor simple
RbXe Cs
Tl
FrE
nhan
cem
ent f
acto
r
Heaviest Alkali metal ~ Francium : ⇒simple electronic structure and large nucleus ⇒Enhancement of EDM ~ largest ! : 210Fr ~ K=1150
Several isotopes with long lifetime > 1 min. ⇒210Fr =3.2 min., 212Fr =19.3 min.
No stable isotopes, but traps compensate scarcity Magneto-Optical Trap (MOT) : localize the trapped atoms
⇒systematic error reduced Temperature of MOT cloud < mK ~ Doppler-free spectroscopy
Presented by Dr.Giulio Stancari @ INFN Ferrara at ISOLDE workshop at CERN, Feb.2006
Fr from the decay of 225Ac
EDM search in the world
MOT+Laser Trap
MOT+Laser Trap
Atomic beamMOTMOT/PenningMOTTrap
171Yb (p) KyotoXe (p)Tokyo Tech.
TISOLTRIUMF~10-27Best limit 205Tl (e)California / LBL
~10-28This proposal210-212FrRCNP
First beam Ra (p)TRIuPKVIAtomic structure210FrSUNY
Goal Status Elements ProjectInstitute
Dy,Sm,BaFr
Yb
205TlRa
129Xe 3P2
Others199HgRn129Xe 1S0Nucleus OthersFe3+CsRbElectron
Elements EDM
ExperimentFrancium Production with Heavy Ion Fusion Reaction :
197Au(18O,xn)209-211Fr
18O beam from AVF cyclotron
Au targetY neutralizer Trapped Francium
Laser Beam
Fr+ ion
Surface Ionizer
EDM search
High intensity ECR ion source
Nuclear Physics
Magneto-Optical Trap
Atomic Physics Particle Physics
TRV SUSY…
Fundamental interaction
Super Conducting ECR Heavy Ion SourceLaser Trap
Apparatus
Ring CyclotronNew Beam Line for Fr Production
New Beam LineLaser Trap
Overview at RCNP
AVF Cyclotron
Ring Cyclotron
ECR ion source
Planned layout of beam line
Primary beam
SC ECR ion source
6 pμA1.1 pμ A
Beam intensity (expected)
~ 100 MeV 18O6+ beam from AVF cyclotronNew ion source : 18GHz Superconducting ECR
For heavy ion and polarized 6Li beam Construction ~ completed soonOperation test ~ will be done next weekMaximum intensity
~ radiation protection limit: 6 puA
Extracted beam
To AVF
Francium production
Fusion Reaction :18/16O + 197Au → 207-211Fr + Xn
Francium desorbs from the target surface as atoms/ions according to
−
=+
kTEE
nn IPWFexp
21
0
18O beam from AVF
Au target Y targetFr+ ion
Fr atom
To Trap/Cooling
Surface ionizer Neutralizer
18O+197Au Fr production
0.01
0.1
1
10
100
1000
50 70 90 110 130
beam energy (MeV)
Cro
ss s
ecti
on (
mb)
212Fr 211Fr 210Fr 209Fr 208Fr
18O+197Au
19F+198Pt Fr production
0.01
0.1
1
10
100
1000
50 70 90 110 130
Beam Energy
Cro
ss S
ection (
mB
)
212Fr 211Fr 210Fr
19F+198Pt
Target : Gold (Au) ~ EWF(5.1eV)>EIP(4.1eV) → Fr+ ionTarget : Yttrium (Y) ~ EWF(3.1eV)<EIP(4.1eV) → Fr atom
210Fr
212Fr
18O+197Au
Fr
Rn
At
Po
Bi
209 210 211
206 207 208
209 210
207 208
204 205 206
Ionization Potential
(eV)
3.83
10.748
9.65
8.43
7.289
Focal Plane for beam diagnosis
New beam line
Focal Plane
Dispersive Transport Achromatic Transport
Vertical Vertical Horizontal Horizontal
Beam size <120mm
Beam energy resolution Beam emittance &Beam transport
Function as spectrometer
Surface Ionizer
Fr+ ion to Magneto-Optical Trap
Primary beam
18O beam from AVF1 4 7
10
13
16
19
22
25
28
31 n
1
10
100
1000
10000
event(arb. unit)
energy (MeV)
particle
emitted particles
n p alpha gamma
Neutron ~ a few MeV⇒ damage to detector (CCD etc..)⇒ MOT should be located
far from production target
New Beam Line for EDM search experiment
For EDM CollaborationK.Hatanaka, A.Tamii, S.Morinobu, Y.Shimizu, K.Fujita, Y.Tameshige, H.Matsubara,T.Kaneda (RCNP)
K.Imai, Y.Takahashi, T.Murakami (Kyoto Univ.)T.Wakasa (Kyushu Univ.), Bhanau P. Das (Indian Institute of Astrophysics)
Surface ionizer will be set here
Beam transport and diagnosis with new beam line
Beam ~ 2 components
Phase slit adjustments ~ 1 component ~ higher transmission
Before AVF tuning Construction ~ completed Transport test with 18O beam ~ completed Beam diagnosis ~ routinely used for high resolution beam preparationTransmission ~ more than 90 % ~ depend on beam emittance
After AVF tuning
AVF accelerator turn ~ separation good
Surface ionizer
197Au disk on W support rod 1200 K for surface ionizer 3 kV to extract Fr+ ion Fusion reaction : 197Au(18O,xn)215-xFrFocusing elements ~ design with 3d field calculation
Design ~ almost finished Construction ~ will be completed in this summer 30 mg/cm2
Fr production
100 mg/cm2 ~50 um
18O Beam
Based on Surface ionizer at SUNY
Au (just below the melting point)
W(Tungsten rod)
Design : Surface ionizer
+ Focus elements
Extracted Fr beam
Francium ion transport
Fr production target •Focus point •Beam size tuning ~ possible •Surface ionizer locate
Laser Trap
Concrete shield Fr+ ion beam Electrostatic lenses
Einzel lens + electrostatic Q lens
NeutralizerOven (Y) temperature : 1000 K ~ heater temperature for Fr atom releaseCapturing velocity of MOT : Vc~1 m/sFraction of trapping atoms : 10-4 ~ 10-5
High trapping efficiency realization ~ need to cool atoms
Velocity distribution
0
0.0005
0.001
0.0015
0.002
0.0025
0.003
0.0035
0 100 200 300 400 500 600 700 800
Atom velocity (m/s)
frac
tion
210Fr@T=1000K 85Rb@T=568K
vFr~281 m/s, vrms~345 m/s
vRb~333 m/s , vrms~408 m/s
Heater
Material surface
LED
Fr ion
Fr atom
Laser cooling and trapping
Goal : Temperature ~ μK
Fr atom beam
Transverse coolingEDM proving region
Magneto-OpticalTrap (MOT)
Decelerating laser
Optical Dipole TrapFiber Laser used
Buffer gas cooling
Laser cooling
Trap Chamber
Science Chamber
Trap view
Trap: 718nm Repump: 817nm
F=11/2
F=13/2
F=9/2
F=11/2F=13/2F=15/2
46.8 GHz
397 MHz500 MHz
617 MHz
7s2S1/2
7p2P3/2
Trap laser : 718 nm and 817 nmExternal Cavity LD (ECLD) + Taper amplifierFabrication ~ in progress
Beam diameter ~ 30 mmAnti-helmholz coil ~ 10 G/cm Pyrex cell with dryfilm coatingDecouple MOT from target area (radiation and vacuum)Laser for Optical Dipole trap : red detuned
High power fiber laser used
ECLD+Taper amp.
ECLDTaper amp.
~ 1W
MOPA configuration : Master oscillator ~ ECLD ~ 10 mWPower amplifier ~ Taper amp. ~ 1 W
Low cost Compact
LD
Grating What should be solved !~ 718 nm Taper amp …
ECLD
MOT Anti-Helmholz coil
Trap Cell
σ+ σ-
Magnetic field gradient~ 5 G/cm
σ+σ- σ-σ+M=-1, 0, 1 M=-1, 0, 1
10 cm
Cooling atoms
( )( )[ ]
Laser
cvbounces
cvDnLasercMOTDntrap
vPfN
vPfvPP εεηεεη ⋅−
−−
⋅⋅=⋅⋅⋅=
1
1
1111
)(Goal : Cooled atom number ~ 108 → Trap efficiency : Ptrap~ higher !
ηn Neutralizer efficiency : material, LEDεD Decelerator efficiency : Collimation laserPMOT MOT efficiency : Decelerator
fv trap size : Laser sizeP1 trap efficiency : Laser detuning, powerNbounce Bounce : Coating, LED
εLaser Laser trap efficiency : Laser power
Efficiency with Decelerator
0
0.2
0.4
0.6
0.8
1
1.2
star
t
Neutra
lizer
Decele
rato
r
MOT
Trap Cell
Bounc
e
Lase
r Tra
p
Cooling/Trapping item
Eff
icie
ncy
Efficiency Total efficiency
Efficiency w/o Decelerator
0
0.2
0.4
0.6
0.8
1
1.2
star
tNeu
traliz
erDec
elera
tor
MOT Tra
p
Cell
Bounc
e
Lase
r Tra
p
Cooling/Trapping item
Eff
icie
nc
y
Efficiency Total efficiency
Buffer gas cooling
Cooled Fr distribution
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
0 2 4 6 8 10 12 14 16 18 20
Velocity (m/s)
fra
cti
on
[email protected]/s [email protected]/s Fr@1m/sCapturing velocity ~ 1 m/s
0.66
0.040.001
Velocity distribution
0
0.02
0.04
0.06
0.08
0.1
0 100 200 300 400Velocity
Fra
ctio
n
Fr@1000K Fr@1K [email protected] [email protected]
Buffer gas cooling ~ J.M.Doyle@HarvardApparatus delivered from HarvardStarted to check the feasibility at Kyoto
LHe bath at 5 K
LN2 bath at 77 K
BufferGas (He)
Cell
Ablation YAG
Atomic beam
Cooling
He
EDM measurement
Ramsey’s method of Separated Oscillatory Fields ~ Atomic beam
Larmor frequency determination by Faraday Rotation measurement~ Trapped atom
Ramsey’s method ElectronElectron
LaserRF B-field
RF B-fieldLaser
tEdF
tEdF
a
a
⋅⋅−∝
⋅⋅+∝
−
+
2121
Faraday rotation measurement
Linier polarization Medium
Faraday Rotation angle : φB
Optical Pumping Laser ~ Atom polarized
Spin precession : ω
Prove laser
( ) ( )θωτφ +⋅−⋅Ψ= TT sinexp
E
Eda ⋅⋅=∆⋅ 4ωh
Fr EDM search timeline accyracy
1.0E-29
1.0E-28
1.0E-27
1.0E-26
1.0E-25
0 5 10 15 20 25 30 35
measurement time (days)
ED
M a
ccura
ct
(e c
m)
210Fr 210Fr+high extraction210Fr+high intensity 212Fr212Fr+high extraction 212Fr+high intensity
SUSYLarge CP phase
SUSYSmall CP phase
Current limit ~ 205Tl 5yeras data
SUNY
Phase1 ~surface ionizer
Phase2 ~ion source
Phase3 ~MOT
2007/LHC start2009/LHC high luminosity
Goal
2005
2006
2007
2008
2009
•Proposed at RCNP•Beam line constructed•ECR ion source•Surface ionizer •MOT ~ ready•Fr production test•Atom cooling test•Shakedown everything•Fr trap optimization •Test experiment (Phase1)•Data taking •Phase2,Phase3….
To achieve de < 10-28 e・cmHigh intensity beam : 6 puA⇒SC ECR ion source Trapped atom ~ increased : 108
⇒MOT with Cooling
EDM in Japan
CPT Models Particle Hadron Nuclear Atom RCNP
J-PARC RIKENProf.Asahi-san’s group : Xe…
Other radioactive atoms..
KM
Higgs
SUSY
LR, Strong CP…
de
dq
dqC
dn
dpara
ddiaQschiff
One may miss something essential by focusing on ONE EDM only!
Next step
15N+205Ta→213Ra+7n
Next species
Nuclear EDM with diamagnetic atoms at RIBF@RIKEN High intensity heavy ion beam ~ 15N5+ : 50 MeV/uMany experts on atomic physics, quantum optics, …Magnetic separator, RFQ decelerator …
Detailed study should be done, But interesting ..
Summary Permanent EDM search
To find Physics beyond standard model, Supersymmetry, …Offer a nice way to approach new physics at low energy
EDM search at RCNP ~ development in progressIn the mean time: experimental apparatus preparation ECR ion source, beam line, surface ionizer, buffered gas cooling, MOT …Test experiment ~ should be ready in 2007..
We need NOT one EDM experiment, BUT MANY experiments needed !
Electron EDM : Paramagnetic atom ~ Fr at RCNP
Nucleus EDM : Diamagnetic atom ~ Xe and extend heavy radioactive atoms at RIBF
Lepton Flavor Violation (LFV) planned at PRISM(@J-PARC…)
New approach promise the significant progress to new physics. Let’s just do it together ! Thank you.
CPe
eUeBrd ϕγµ
⋅××→
− 1.0102.1)(~ 3
11: EDM and LFV ~ correlation