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Klaus.Kirch@psi.ch 1Krakow, June 2010
The search for permanent electric dipole moments
Klaus Kirch ETH Zürich & PSI Villigen
CP violation and electric dipole momentsSystems to work with and their connection to CPVarious comments on the wayInternational status and expectations
Meson2010, June 14th, 2010
Klaus.Kirch@psi.ch 2Krakow, June 2010
What caused the Baryon asymmetry ?
Observed*:(nB-nB) / n = 6 x 10-10
SM expectation:(nB-nB) / n ~ 10-18
Sakharov 1967: B-violationC & CP-violationnon-equilibrium[JETP Lett. 5 (1967) 24]
* WMAP + COBE, 2003 nB / n = (6.1 ± ) x 10-100.3
0.2
_
_
Klaus.Kirch@psi.ch 3Krakow, June 2010
EDM and symmetries
+_
+_
+
_P
TA nonzero particle EDM violates P, T and, assuming CPT conservation, also CP
Purcell and Ramsey, PR78(1950)807; Lee and Yang; Landau
Klaus.Kirch@psi.ch 4Krakow, June 2010
M. Raidal et al., Eur. Phys. J. C 57 (2008) 13
Adapted from:Pospelov, Ritz, Ann. Phys. 318 (2005) 119
,ThO)
EDMs of paramagneticatoms & molecules
Tl,Cs..,YbF,PbO,ThO,HfF+,WC..
neutron & proton EDMs
EDMs of diamagnetic atoms
Hg, Xe, Ra, Rn ..
Solid stateEDM effects GdIG,GdYIG,(EU,Ba)TiO3
AstrophysicalEDM effects neutron stars
Origin of EDMs
Klaus.Kirch@psi.ch 5Krakow, June 2010
M. Raidal et al., Eur. Phys. J. C 57 (2008) 13
Adapted from:Pospelov, Ritz, Ann. Phys. 318 (2005) 119
,ThO)
EDMs of paramagneticatoms & molecules
Tl,Cs..,YbF,PbO,ThO,HfF+,WC..
neutron & proton EDMs
EDMs of diamagnetic atoms
Hg, Xe, Ra, Rn ..
Solid stateEDM effects GdIG,GdYIG,(EU,Ba)TiO3
AstrophysicalEDM effects? neutron stars, ..
Origin of EDMs
This is what we need
Klaus.Kirch@psi.ch 6Krakow, June 2010
M. Raidal et al., Eur. Phys. J. C 57 (2008) 13
Adapted from:Pospelov, Ritz, Ann. Phys. 318 (2005) 119
,ThO)
EDMs of paramagneticatoms & molecules
Tl,Cs..,YbF,PbO,ThO,HfF+,WC..
neutron & proton EDMs
EDMs of diamagnetic atoms
Hg, Xe, Ra, Rn ..
Solid stateEDM effects GdIG,GdYIG,(EU,Ba)TiO3
AstrophysicalEDM effects? neutron stars, ..
Origin of EDMs
This is what we need
These we can access
Klaus.Kirch@psi.ch 7Krakow, June 2010
M. Raidal et al., Eur. Phys. J. C 57 (2008) 13
Adapted from:Pospelov, Ritz, Ann. Phys. 318 (2005) 119
,ThO)
EDMs of paramagneticatoms & molecules
Tl,Cs..,YbF,PbO,ThO,HfF+,WC..
neutron & proton EDMs
EDMs of diamagnetic atoms
Hg, Xe, Ra, Rn ..
Solid stateEDM effects GdIG,GdYIG,(EU,Ba)TiO3
AstrophysicalEDM effects? neutron stars, ..
Origin of EDMs
This is what we need
These we can access
These should be deduced
Klaus.Kirch@psi.ch 8Krakow, June 2010
M. Raidal et al., Eur. Phys. J. C 57 (2008) 13
Adapted from:Pospelov, Ritz, Ann. Phys. 318 (2005) 119
,ThO)
EDMs of paramagneticatoms & molecules
Tl,Cs…,YbF,PbO,ThO,HfF+,WC..
neutron & proton EDMs
EDMs of diamagnetic atoms
Hg, Xe, Ra, Rn ..
Solid stateEDM effects GdIG,GdYIG,(EU,Ba)TiO3
AstrophysicalEDM effects, neutron stars, ..
Direct limitsActive R&D
Origin of EDMs
Klaus.Kirch@psi.ch 9Krakow, June 2010
EDM-Search Strategy I
Today: Discovery experimentsnot known which EDM will show up first
search in as many accessible complementary systems as possible
Once discovered:Increase precision (experiment and theory)
Complementary EDM results will constrain models of new physics or even single out the origin of the observed effects
Klaus.Kirch@psi.ch 10Krakow, June 2010
EDM-Search Strategy II
Maximize experimental sensitivity need large polarized sample statistics
need large electric fields
need excellent magnetic field control
the signal is due to the interaction of minute EDMs with an electric field in the presence of magnetic moments and magnetic fields
many background and noise sources and false effects exist, usually related to the electro- magnetic fields
Klaus.Kirch@psi.ch 11Krakow, June 2010
Standard Model EDM-expectations?
Leptons: electroweak negligible
Neutron, proton, nuclei: electroweak negligible, strong?
Klaus.Kirch@psi.ch 12Krakow, June 2010
Standard model lepton EDMsFourth order
electroweak,
F. Hoogeveen:The Standard Model Prediction for the Electric Dipole Moment of the Electron,Nucl. Phys. B 241 (1990) 322
… + new physics?
Klaus.Kirch@psi.ch 13Krakow, June 2010
Fourth order electroweak,
F. Hoogeveen:The Standard Model Prediction for the Electric Dipole Moment of the Electron,Nucl. Phys. B 241 (1990) 322
… + new physics? Much greater sensitivity to new, CP-violating physics!
Completely negligible at any experimental sensitivity we can imagine today!
Standard model lepton EDMs
Klaus.Kirch@psi.ch 14Krakow, June 2010
Fourth order electroweak,
F. Hoogeveen:The Standard Model Prediction for the Electric Dipole Moment of the Electron,Nucl. Phys. B 241 (1990) 322
… + new physics? Much greater sensitivity to new, CP-violating physics!
Completely negligible at any experimental sensitivity we can imagine today!
Standard model lepton EDMs
Expect from SM,approximately:
de ≤ 10-38 e•cmd≤ 10-36 e•cmd ≤ 10-35 e•cm
Experimentally so far:
de< 2 x 10-27 e•cmd< 2 x 10-19 e•cmd< 3 x 10-17 e•cm
10-27 10-27
10-2810-28
exclu
ded
exclu
ded
excluded
excluded
Klaus.Kirch@psi.ch 16Krakow, June 2010
The historyof neutron
EDM limits
10-26
10-20 10-20
10-26
1950 2000
ED
M u
pper
lim
it [e
cm
]
Smith, Purcell, Ramsey PR108(1957)120
[e cm]
.
Electro-weak standard modelexpectation: ~10-32 e•cm
RAL-Sussex-ILL dn < 2.9 x 10–26 e cmC.A.Baker et al., PRL 97 (2006) 131801
Klaus.Kirch@psi.ch 17Krakow, June 2010
10-26
10-20
1950 2000
ED
M u
pper
lim
it [e
cm
]
[e cm]The strong CP problem
.
dn ≈ 10-16 e cm • QCD
QCD < 10-10~
LQCD ≈ LQCD + g2/(322) QCDGGQCD=0 ~
Why is QCD so small ?
QC
D
Klaus.Kirch@psi.ch 18Krakow, June 2010
The SUSY CP problem
.
10-26
10-20
1950 2000
ED
M u
pper
lim
it [e
cm
]
[e cm]
dn ≈ 10-23 e cm ( )sinSUSY
300 GeV/c
MSUSY
22
SU
SY
Why is SUSY so small ?
Pospelov, Ritz, Ann. Phys. 318(2005)119 for MSUSY = 500GeV, tan = 3
(for neutron and electron!)
Klaus.Kirch@psi.ch 19Krakow, June 2010
The state of the art …Class EDM Exp. bound [ecm] Reference
bare lepton < 1.8 x 10-19 PRD80(2009)052008
nucleon n < 2.9 x 10-26 PRL97(2006)131801
diamagnetic 199Hg < 3.1 x 10-29 PRL102(2009)101601
paramagnetic 205Tl < 9 x 10-25 PRL88(2002)071805
Klaus.Kirch@psi.ch 20Krakow, June 2010
… and some comments:
The state of the art …Class EDM Exp. bound [ecm] Reference
bare lepton < 1.8 x 10-19 PRD80(2009)052008
nucleon n < 2.9 x 10-26 PRL97(2006)131801
diamagnetic 199Hg < 3.1 x 10-29 PRL102(2009)101601
paramagnetic 205Tl < 9 x 10-25 PRL88(2002)071805
Klaus.Kirch@psi.ch 21Krakow, June 2010
… and some comments:
enhancementfactor smaller limit weaker
with additional assumption concerning eN interaction
The state of the art …
205Tl is not the most precise EDM experiment, but
Class EDM Exp. bound [ecm] Reference
bare lepton < 1.8 x 10-19 PRD80(2009)052008
nucleon n < 2.9 x 10-26 PRL97(2006)131801
diamagnetic 199Hg < 3.1 x 10-29 PRL102(2009)101601
paramagnetic 205Tl < 9 x 10-25 PRL88(2002)071805
Klaus.Kirch@psi.ch 22Krakow, June 2010
Klaus.Kirch@psi.ch 23Krakow, June 2010
… and some comments:
suppression of order 103
The state of the art …
199Hg is the most precise EDM experiment by 3 orders, but
Class EDM Exp. bound [ecm] Reference
bare lepton < 1.8 x 10-19 PRD80(2009)052008
nucleon n < 2.9 x 10-26 PRL97(2006)131801
diamagnetic 199Hg < 3.1 x 10-29 PRL102(2009)101601
paramagnetic 205Tl < 9 x 10-25 PRL88(2002)071805
Klaus.Kirch@psi.ch 24Krakow, June 2010
… and some comments:
The state of the art …Class EDM Exp. bound [ecm] Reference
bare lepton < 1.8 x 10-19 PRD80(2009)052008
nucleon n < 2.9 x 10-26 PRL97(2006)131801
diamagnetic 199Hg < 3.1 x 10-29 PRL102(2009)101601
paramagnetic 205Tl < 9 x 10-25 PRL88(2002)071805
The muon entry is the only one measured with charged particles.The experiment was performed in a storage ring, the techniquecould be considerably improved in the future. It also serves as a demonstration for storage ring EDMs that are planned withprotons (BNL) and deuterons (COSY) and may be other ions.
Klaus.Kirch@psi.ch 25Krakow, June 2010
… and some comments:
The state of the art …Class EDM Exp. bound [ecm] Reference
bare lepton < 1.8 x 10-19 PRD80(2009)052008
nucleon n < 2.9 x 10-26 PRL97(2006)131801
diamagnetic 199Hg < 3.1 x 10-29 PRL102(2009)101601
paramagnetic 205Tl < 9 x 10-25 PRL88(2002)071805
The neutron remains the classic example and is being pushed forward today by at least 4 international collaborations with somewhat different approaches. A future combination with resultsfrom proton and deuteron would allow to disentangle a possible QCD contribution to the nucleon EDMs.
Klaus.Kirch@psi.ch 26Krakow, June 2010
MolecularYbF beam (Imperial) World-leading result in preparation. 1×10-29 e cm over 5 yrs.PbO* cell (Yale) Ending because of systematic errors.ThO beam (Harvard/Yale) “5 yrs from 1st result aiming at 10-29 e cm”PbF beam (Oklahoma) Just starting - “10 years from measurement”HfO+ (Boulder) trap “Serious measurement far away”. Might reach 1×10-29 e cmWC (Michigan)
AtomicThallium beam (Berkeley) Current world limit, but has gone as far as possible.Ultracold Cs in a lattice (Penn State). Probably 10 years from measurement.
Solid stateSpins in ferroelectric solids (Yale, Amherst, Indiana) Macroscopic sample. Low noise. Previous solid experiments had huge systematics, potential accuracy unknown.
Leading alternative approaches to eEDM
Courtesy: Ben Sauer
Klaus.Kirch@psi.ch 27Krakow, June 2010
IonsProton storage ring (Brookhaven) R&D ongoing Deuteron storage ring (FZ Jülich) R&D ongoingOther ion EDMs in storage rings possible, and similarly muons (JPARC, PSI)
Atoms199Hg (Seattle) World-leading result: 3×10-29 e cm, next improvement: factor ~ 5.129Xe (Princeton, Munich) R&D ongoing213,225Ra (Argonne, Groningen) R&D ongoingRn (Triumf)
Leading alt. approaches to nuclear EDMs
Courtesy: Ben Sauer
NeutronsSussex-RAL-ILL World-leading result: 3×10-26 e cm, apparatus was moved to PSIPNPI-ILL: towards 10-26 e cm in 2012nEDM collaboration at PSI: ~ 5 x 10-27 e cm in 2012n2EDM (collaboration see nedm.web.psi.ch): 5 x 10-28 e cm in 2016Sussex-RAL-ILL-Oxford-Kuore (at ILL): similar time scale as n2EDMUS collaboration at SNS: 8 x 10-28 e cm after 2020Developments at JPARC, TRIUMF, and maybe other places
Klaus.Kirch@psi.ch 29Krakow, June 2010
Beam dump
nEDMn
• Source commissioning started fall 2009• Expect 1000 UCN/cm3 in typical experiments
(compare to currently 10 UCN/cm3 at ILL)• nEDM setting up since middle of 2009
PSI UCN Source
Klaus.Kirch@psi.ch 30Krakow, June 2010
Klaus.Kirch@psi.ch 31Krakow, June 2010
Present best limit: dn < 2.9 x 10-26 ecm
Sussex-RAL-ILL collaborationC. A. Baker et al., PRL 97 (2006) 131801
nEDM collaboration nedm.web.psi.ch15 groups, 50 people
Moved from ILL to PSI March 2009
Data taking at PSI 2010 – 2012 .. (Phase II)Sensitivity goal: 5x10-27ecm (95% C.L.)
Operation of new n2EDM apparatus 2012 – 2016 .. (Phase III)
Sensitivity goal: 5x10-28ecm (95% C.L.)
Klaus.Kirch@psi.ch 32Krakow, June 2010
Please mark your calendars for the
2nd International Workshop on the
Physics of fundamental Symmetries and
Interactions – PSI2010 October 11-14, 2010 at the Paul Scherrer Institut, CHThe focus is on physics at the low energy, high precision frontier and related topics.psi2010.web.psi.ch
Klaus.Kirch@psi.ch 33Krakow, June 2010
Conclusions
Thank you !
Klaus.Kirch@psi.ch 34Krakow, June 2010
Klaus.Kirch@psi.ch 35Krakow, June 2010
How to measure the neutron(or other) electric dipole moment ?
B E
h= 2 (μB+dn E)h = 2 (μB- dnE)
h = 4 dn E
Klaus.Kirch@psi.ch 36Krakow, June 2010
Thallium edm
Thallium-EDM experiment
Klaus.Kirch@psi.ch 37Krakow, June 2010
199Hg EDMOptically pumped 199Hg atoms precess in B & E fields, modulating absorption signal. Multiple cells remove effects of B drift.
Result: d(199Hg) < 3 x 10-29 e cm PRL 102 (2009) 101601
Provides good limit on CPv effects in nuclear forces, inc. QCD
“Confirms” dn<6x10-26 ecm.
Klaus.Kirch@psi.ch 38Krakow, June 2010
Present nEDM limit
C. A. Baker et al., PRL 97 (2006) 131801P. G. Harris et al., PRL 82 (1999) 904
Sussex-RAL-ILL experiment
dn < 2.9 x 10-26 e cm (90%CL)
Klaus.Kirch@psi.ch 39Krakow, June 2010
Special feature: co-magnetometer
·· · · · · ·
· ·· · ··· ··· ·· · ··
·· ·
BoEUCN
199Hg
K.Green et al., NIM A 404 (1998) 381 P. G. Harris et al., PRL 82 (1999) 904
199Hg co-magnetometer
50 pT
Klaus.Kirch@psi.ch 40Krakow, June 2010
Next generation of experiments will …
… perhaps establish a finite value !!
Courtesy: A. Knecht
… in any case, severely constrain non-SM physics
Klaus.Kirch@psi.ch 41Krakow, June 2010
Summary of leading nEDM exptsGroup # people Anticipated
sensitivity (ecm)
By...
UK: CryoEDM ~25 ~3E-27 2012
CryoEDM (new beamline)
~30?* ~3E-28 2016?
SNS-EDM ~90 <1E-28? >2020
nEDM@PSI ~50 ~5E-27~5E-28
20122016?
PNPI/ILL ~10-20? ~1E-26 2012?
Courtesy: Phil Harris – slightly modified
Klaus.Kirch@psi.ch 42Krakow, June 2010Paul Scherrer Institut Swiss Light Source (SLS)3. generation synchrotron
Proton accelerator: 600 MeV, 2.2 mA, 1.3 MW(upgrade program 3 mA)muons, pions and neutronsfor fundamental and appliedresearch
New UCN source
Proton therapy
New project:SwissFEL
Research on:• Energy• Nuclear safety• Structural biology, chemistry
Klaus.Kirch@psi.ch 43Krakow, June 2010
3.6 m3 D2O
UCN~6000 cm-3
2 m3 volumestorage trap
~ 2000 cm-3exp> 1000 cm-3
The PSI UCN source
UCN guide
30 liters solid D2
vacuum
• high power (1.3 MW)• low duty cycle (1%) • multi-user capability
compare with typical 10 cm-3 at ILL
p-beam 1.3 MW
Klaus.Kirch@psi.ch 44Krakow, June 2010
n[cm-2s-1]
Vc[dm3]
VUCN[dm3]
Tc[K]
Pc[W]
RUCN[cm-3s-1]
UCN[s]
UCN
[cm-3]
PSIspallation1% of 1.3MW
2.6 x 1013
pulsed (1%)30D2
2000 5 ~10Wavg.
3 x 105 10
400
1‘000in exp.
ILL
beam
1 x 1010
cw1-
1000.8 ~mW 30 100 1‘000
in exp.
FRM-IIreactor
4.5 x 1013
cw0.1D2
80 - 800
5 ~10W 5 x 105 30 3‘000dep vol
PNPIreactor
2 x 1012
cw35 100 -
4001.2 ~20W 4 x 103 30 10‘000
TRIUMFspallation25% of 20kW
2 x 1012
cw (25%)10 100 0.8 ~8W 4 x 103 150 50‘000
201
0≥2
010
≥201
2>
2013
My biased & personal summary table
Klaus.Kirch@psi.ch 45Krakow, June 2010
Storage ring EDMs
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