+ - Status of the proton EDM experiment at BNL Yannis K. Semertzidis Brookhaven National Laboratory Motivation Neutron EDM experiments Status of Storage Ring EDM experiments (proton & deuteron) Plan XXIX Workshop on Recent Advances in Particle Physics and Cosmology Patrai, April 2011

The great mystery in our universe: matter dominance over anti-matter Observations From SM (CKM- Weak interactions):

In Quantum Mechanics: a non- degenerate system with Spin is defined by the spin vector + - If the particle has an EDM, its vector needs to be aligned with the spin vector, locked to its direction, i.e. it needs to choose either along or opposite but not both (non- degenerate). “CP-Violation Without Strangeness”, Khriplovich/Lamoreaux.

A Permanent EDM Violates both T & P Symmetries: T P

Yannis Semertzidis, BNL The Electric Dipole Moment precesses in an Electric field + - The EDM vector d is along the particle spin direction

A charged particle between Electric Field plates would be lost right away

Measuring an EDM of Neutral Particles H = -(d E + μ B) ● I/I m I = 1/2 m I = -1/2 ω1ω1 ω2ω2 d EB µ d µ EB d = e cm E = 200 kV/cm  = rad/s  ~1 turn/year 

Spin precession at rest Compare the Precession Frequencies with E-field Flipped: + -  Yannis Semertzidis, BNL

Main Systematic Error: particles have non-zero magnetic moments! For the nEDM experiments a co-magnetometer or SQUIDS are used to monitor the B-field: cancellation level needed for e-cm is of order 3pG.

Yannis Semertzidis, BNL Important Stages in an EDM Experiment 1.Polarize:state preparation, intensity of beams 2.Interact with an E-field:the higher the better 3.Analyze:high efficiency analyzer 4.Scientific Interpretation of Result! Easier for the simpler systems

EDM Experiments Statistics is of the essence (number of neutrons, spin coherence time,…) Systematics is close second (magnetic fields, geometrical phases,…)

Yannis Semertzidis, BNL nEDM experiment at ILL (Grenoble):

Yannis Semertzidis, BNL New UCN experiment at ILL: Expect a factor of ~100 improvement in sensitivity due to Neutrons in 0.5 K He bath ~50  more neutrons E-field: 4-6  at cryo temp. Longer coherence times

Neutron EDM at PSI

Lower Cryostat Upper Cryostat ~6 m DR LHe Volume ~450 liters Upper Cryostat Services DR Central LHe Volume ~400 mK, ~1000 liters Reentrant Neutron Guide ABS Line 3He Injection Volume 4-layer  -metal shield 3He Injection Volume Cos  magnet ABS SNS nEDM Experiment - Vertical Section View The current value is < 3 x ecm (90% C.L.) Hope to obtain roughly < 8 x ecm with UCN in superfluid He

Yannis Semertzidis, BNL Neutron EDM Timeline E-24 1E-26 1E-28 1E-30 1E-32 EDM Limits [e  cm] ILL, n PSI, n SNS, n Year

Storage Ring EDM experiments (or how to create a Dirac-like particle in an electric storage ring)

A charged particle between Electric Field plates would be lost right away… - + +

Yannis Semertzidis, BNL …but can be kept in a storage ring for a long time E E E E

Yannis Semertzidis, BNL The sensitivity to EDM is optimum when the spin vector is kept aligned to the momentum vector Momentum vector Spin vector E E E E

Yannis Semertzidis, BNL The spin precession relative to momentum in the plane is kept near zero. A vert. spin precession vs. time is an indication of an EDM (d) signal. E E E E

Freezing the horizontal spin precession The spin precession is zero at “magic” momentum (0.7 GeV/c for protons, 3.1GeV/c for muons,…) The “magic” momentum concept was first used in the last muon g-2 experiment at CERN and BNL.

Yannis Semertzidis, BNL When P=P magic the spin follows the momentum E E E E No matter what the E-field value is the spin follows the momentum vector creating an ideal Dirac-like particle (g=2) 1.Eliminates geometrical phase effect 2.Equalizes the beta-functions of counter-rotating (CR) beams 3.Closed orbits of the CR beams are the same

There is an asymmetry between E and B-fields and g-2 precession B-fields: Independent of velocity! E-fields: Depends on velocity

Freezing the horizontal spin precession for the proton a=1.79, and deuteron a= For particles with negative anomalous magnetic moment there is no …magic. A dipole B-field is required to cancel the g-2 precession in the deuteron case

Storage Ring EDM experiments: 1.High beam intensities ( ), with high polarization (>0.8), and low emittance are currently available 2.Large electric fields are possible (10-20MV/m) 3.Spin coherence time ~10 3 s are possible 4.High efficiency, large analyzing power (~0.5) polarimeters are available for the proton and deuteron at ~1 GeV/c momentum making possible the next sensitivity level 5.Direct access to charged particle EDMs

extraction adding white noise to slowly increase the beam phase space “defining aperture” polarimeter target carries EDM signal increases slowly with time carries in-plane precession signal pEDM polarimeter principle: probing the proton spin components as a function of storage time Micro-Megas TPC detector and/or MRPC

Micro-Megas TPC tests at Saclay by the Demokritos group G. Fanourakis, et al.

Micro-Megas based polarimeter Pointing capability High rate operation MM-TPC (Demokritos) MM-Telescope (Demokritos) Electronics/DAQ: Univ. of Patras Univ. of Thessaloniki

Proton at its magic momentum We had two successful technical reviews 1.December 2009, with a subsequent scientific approval at BNL. 2.March 2011 Both reviews are strongly encouraging the collaboration to pursuit the method due to its great physics reach. No surprises, no show-stoppers, several great suggestions We are preparing a proposal to DOE to be submitted within the next two months

Rough cost range (contingency of % is included) Experiment (~$40M) Ring construction (~$18M) (new construction) Beamline (~$12M) R&D: two years Requested funding for R&D: $3M

Novelty The largest radius electric ring in the world: ~30-40m Proton (magic) kinetic energy: 233 MeV Proton (magic) momentum: 0.7 GeV/c Magic: In an electric ring, the proton spin precesses exactly as much as the momentum. Protons behave as ideal Dirac-like particles…

Challenges The largest electric ring in the world Reduce low frequency B-field noise by a factor of 3×10 8 with passive (10 5 ) and an active feedback (3×10 3 ) The storage ring is the experiment

Running time plan 1 st year running for systematics and sensitivity goal: e  cm Additional 3 years for better than e  cm statistical sensitivity Required beam: 2×10 10 polarized protons in each direction (electric ring) with small emittances. Beam parameters are already available at BNL.

Main Motivation CP-violation beyond the SM ( TeV), beyond the LHC design sensitivity CP-violation in SM: θ QCD < 0.3× If found, it can help resolve the matter- antimatter asymmetry mystery of our universe At least ten times the best planned neutron EDM sensitivity It can resolve SM vs. non-SM CP-V source

Further prospects Deuteron (requires combination of E- and B- fields) 3 He … The proton at its magic is the simplest of all They all probe different CP-violating sources

EDMs of hadronic systems are mainly sensitive to Theta-QCD (part of the SM) CP-violation sources beyond the SM A number of alternative simple systems could provide invaluable complementary information (e.g. neutron, proton, deuteron,…).

Two different labs to host the S.R. EDM experiments BNL, USA: proton “magic” ring COSY/IKP, Germany: deuteron ring

Booster AGS

Technically driven pEDM timeline Two years R&D One year final ring design Two years ring/beamline construction Two years installation

Electroweak Baryogenises GUT SUSY J.M.Pendlebury and E.A. Hinds, NIMA 440 (2000) 471 e-cm Gray: Neutron Red: Electron n current n target Sensitivity to Rule on Several New Models e current e target p, d target

Physics reach of magic pEDM (Marciano) The proton EDM at e∙cm has a reach of >300TeV or, if new physics exists at the LHC scale,  < rad CP-violating phase; an unprecedented sensitivity level. The deuteron EDM sensitivity is similar. Sensitivity to SUSY-type new Physics: Sensitivity to new contact interaction: 3000 TeV

Summary Physics is a must do, positive or negative result can differentiate between models (BAU) E-field issues understood well Working EDM lattice with long SCT and large enough acceptance (1.3× e  cm/year) We plan to demonstrate feasibility of BPM assumptions including tests at RHIC We are submitting the proposal to DOE within the next two months.

Magnetic shielding (active + passive: 3×10 8 ) 4 layers of 0.062" thick Amumetal with 3" spacing between layers: SF 133K:1 OD 35” Quotation from Amuneal to produce 4 layers of clam shells (legos) ready to be installed.

The EDM signal: early to late change Comparing the (left-right)/(left+right) counts vs. time we monitor the vertical component of spin (L-R)/(L+R) vs. Time [s] M.C. data

After the review committee suggestion (T. Roser) : Take more beam very early and late (L-R)/(L+R) vs. Time [s] M.C. data

Physics strength comparison (Marciano) SystemCurrent limit [e  cm] Future goalNeutron equivalent Neutron<1.6× ~ Hg atom<3× < Xe atom<6× ~ Deuteron nucleus ~ × × Proton nucleus <7× ~

Yannis Semertzidis, BNL Hadronic EDM Timeline E-24 1E-26 1E-28 1E-30 1E-32 EDM Limits [e  cm] ILL, n PSI, n SNS, n BNL, p COSY, d 199 Hg 129 Xe Future 129 Xe, Rn, Ra

Yannis Semertzidis, BNL Electron EDM Timeline E-24 1E-26 1E-28 1E-30 1E-32 EDM Limits [e  cm] Tl, e - Polar mol. Future

Short History of EDM 1950’s neutron EDM experiment: a search for parity violation (before the discovery of P-violation) After P-violation was discovered it was realized EDMs require both P,T-violation 1960’s EDM searches in atomic systems 1970’s Indirect Storage Ring EDM method from the CERN muon g-2 exp. 1980’s Theory studies on systems (polar molecules) with large enhancement factors 1990’s First exp. attempts w/ polar molecules. Dedicated Storage Ring EDM method developed 2000’s Proposal for sensitive srEDM exp. approved; Magn. Opt. Traps developed, progress w/ polar mol.

EDMs of different systems Theta_QCD: Super-Symmetry (SUSY) model predictions:

The results and best limits It now dominates the limits on many parameters They expect another improvement factor ~3 - 5.

Yannis Semertzidis, BNL The spin precession relative to momentum in the plane is kept near zero. A vert. spin precession vs. time is an indication of an EDM (d) signal. E E E E

Vertical plates are placed everywhere around the ring to minimize vertical electric/radial B- fields from image charges E-field plate module: The (26) FNAL Tevatron ES-separators would do 0.4 m 3 m Beam position

Is the polarimeter analyzing power good at P magic ? YES! Analyzing power can be further optimized

Gas cluster ion beam surface treatment

Storage Ring EDM Technical Review – 12/7/2009 Edward J. Stephenson, IUCF15 Polarimeter Development Polarimeter (Half) Polarimeter in the ring: cm One target is shown. We want a target available from at least the left, right, up and down directions. Quadrupoles here are larger aperture for clearance. 5° to 20° acceptance Generic detector: (?) Multi-resistive plate chamber (?) Micro-megas (?) Gas electron multiplier (?) …other Absorber to remove low analyzing power particles. (Detector choice can also give discrimination.) Equal rate readout pads Rate = 800 /s/pad In one store:

Storage Ring EDM Technical Review – 12/7/2009 Edward J. Stephenson, IUCF4 Polarimeter Development COSY ring: Use EDDA detector COSY tests EDDA detector: Rings and bars to determine angles. LEFT UP DOWNRIGHT Azimuthal angles yield two asymmetries:

Storage Ring EDM Technical Review – 12/7/2009 Edward J. Stephenson, IUCF5 Polarimeter Development Target Concept Target solution found at COSY: 15 mm White noise applied to electric field plates. beam core expanded vertical phase space end view maximum allowed at COSY Do enough particles penetrate far enough into the front face to travel most of the way through the target? This requires a comparison of the efficiency with model values.

Polarimeter rates: Beam intensity with 2×10 10 pol. protons/ ~10 3 s and a detection efficiency of 1%  200KHz for ~3000cm 2 area, or ~100Hz/cm 2 on average but much higher at small radius. Design: ~1KHz/pad. 70 cm

Applying Micro-Megas TPC Yannis Semertzidis, BNL Differentiate between protons and deuterons Have a pointing accuracy of 0.5mrad/event

e-EDM experiment with atom in the world EDM of stable alkaline atoms Cesium Fountain EDM experiment (Harvey Gould et al., LBNL, California, USA) Projected accuracy d e ~1× e cm EDM experiment of Cs and Rb in 1-D Optical Lattice (David Weiss et al., Penn. State Univ., USA) Projected accuracy d e ~5× e cm Cesium EDM Experiment using Optical Dipole Force Traps (Heinzen et al., University of Texas, Austin, USA) Projected accuracy d e ~ e cm Cesium EDM Experiment using Optical Lattice (K. Honda, Tokyo Institute of Technology, Tokyo, Japan) Many activities in the world ….

Yannis Semertzidis, BNL Ramsey’s method of separated fields