Search for permanent Electric Dipole Moments

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Search for permanent Electric Dipole Moments

June 3, 2013 Frank Rathmann(on behalf of BNL-EDM and JEDI collaborations)

INPC, Firenze, Italy

2

Outline

Introduction Electric Dipole Moments Charged particle EDM searches

Concepts for dedicated Storage Ring searches Technological challenges Precursor Experiments

News Timeline Conclusion

Search for permanent Electric Dipole [email protected]

3

Introduction: The big challenges

[email protected] Search for permanent Electric Dipole Moments

Conventional HEP wisdom, but there is more than that …


Search forthe origin of

mass („Higgs“),SUSY

Secrets ofneutrinos

Quest for „Dark Matter“

and „Dark Energy“(In-)stability

of theproton

EnergyIntensity

Cosm

ic

Precision

Frontiers of PhysicalSciences

Complexity

Introduction: Physics Frontiers


A most promising additional frontier: Precision

ESPP, Cracow,September 2012

Introduction: Precision Frontier

6

Search for Electric Dipole Moments (EDM) of fundamental particles

Adapted from:Nature,

Vol 482 (2012)

Example: Neutron (nEDM)

Introduction: Precision Frontier


7

Outline





8

Charge symmetric No EDM ()

Do particles (e.g., electron, nucleon) have an EDM?


: MDM: EDM

Physics: Fundamental Particles

[email protected] 9Search for permanent Electric Dipole Moments

Permanent EDMs violate P and T.Assuming CPT to hold, CP violated also.

Not Charge symmetric (aligned w/ spin)

EDMs: Discrete Symmetries

10

Physics: What caused the Baryon asymmetry?


Carina Nebula: Largest-seen star-birth regions in the galaxy

Observed WMAP+COBE (2003)

SM exp.

What happened to the antimatter?

Sakharov (1967): Three conditions for baryogenesis

1. B number conservation violated sufficiently strongly2. C and CP violated, B and anti-Bs with different rates3. Evolution of universe outside thermal equilibrium

The mystery of the missing antimatter (the puzzle of our existence)

11

J.M. Pendlebury: „nEDM has killed more theories than any other single expt.“


Physics: Potential of EDMs

12

Outline






For transverse electric and magnetic fields in a ring ( ),anomalous spin precession is described by Thomas-BMT equation:

0 EB

cE

pmGBG

mq

G

2

Magic condition: Spin along momentum vector

1. For any sign of , in a combined electric and magnetic machine

2. For (protons) in an all electric ring

2

2gG

222

2

1

GBc

GGBcE

x

Gmp

pmG

0

2

cMeV74.700 (magic)

Principle: Frozen spin Method

Magic rings to measure EDMs of free charge particles

• Place particles in a storage ring• Align spin along momentum („Freeze“ horizontal spin precession)• Search for time development of vertical polarization


0G

Edts

dd

Principle: Rings for srEDM searches

New Method to measure EDMs of free charged particles:Magic rings with spin frozen along momentum

(from R. Talman)


pEDM in all electric ring at BNL Jülich, focus on deuterons, or a combined machine

CW and CCW propagating beams

EDMs: Storage ring projects

Two projects: US (BNL or FNAL) and Europe (FZJ)

or at FNAL

2 beams simultaneously rotating in an all electric ring (cw, ccw)

Status: Approved BNL-ProposalSubmitted to DOEInterest FNAL!

Goal for protons


Beat systematics: BNL Proposal

year)(onecme105.2 29 pd

CW CCWPolarization EDM Sokolov-TernovGravitation

CW & CCW beams cancels systematic effects

Many technological challenges need to be met

A magic storage ring for protons (electrostatic), deuterons, …


particleproton

0G

Edts

dd

Principle: Magic Storage ring

Possible to measure , , using ONE machine with m

B

deuteron

CCW & CCW with magnetic field:Richard Talmans concept for a Jülich all-in-one machine

[email protected] Search for permanent Electric Dipole Moments 18

Iron-free, current-only, magnetic bending, eliminates hysteresis

A

B

A BConfiguration generates close-to-perfect vertical B field


particleproton

deuteron

Magic ring: Jülich all-in-one machine (R. Talmans concept )

𝒓=𝟏𝟎𝐦

Maximum achievable field of copper magnets T.

B

Very compact machines possible for srEDM searches

20

No direct measurements for proton and deuteron EDM yet !

EDMs – Sensitivity Reach

Adapted from:Nature,

Vol 482 (2012)

pEDMdEDM

EDM search in charged baryon (systems)


21

Outline


Concepts for dedicated Storage Ring Searches Technological challenges Precursor Experiments




srEDM searches: Technogical challenges

Charged particle EDM searches require development of a new class of high-precision machines with mainly electric fields for bending and focussing.

Other topics:

• Electric field gradients • Spin coherence time • Continuous polarimetry • Beam positioning

• Spin tracking

These issues must be addressed experimentally at existing facilities

23Search for permanent Electric Dipole [email protected]

5 10 15 20 25 30 350

20

40

60

80

100Proton EDM

E-field (MV/m)

radi

us (m

)

r1 E( )

E

r2 250 md 0.48 Gd Zd 8.44

r2 280 m3He 0.0575 G3He Z3He 21.959

𝐸=17 MV /m

𝑟=24.665m

Challenge: Electric field for magic rings

Challenge to produce large electric field gradients

Rfield only


Challenge: Niobium electrodes

Show one slide on JLAB data HV devicesDPP stainless steel fine-grain Nb

large-grain Nblarge-grain Nb single-crystal Nb

Large-grain Nb at plate separation of a few cm yields ~20 MV/m

Search for permanent Electric Dipole Moments [email protected]

Challenge: Electric field for magic ringsElectrostatic separators at Tevatron used to avoid unwanted interactions

- electrodes made from stainless steel

Routine operation at spark/Year at MV/m

L~2.5 m

Need to develop new electrode materials and surface treatments

June 2013: Transfer of separator unit plus equipment from FNAL to Jülich

AAS

one particle with magnetic moment

“spin tune”

“spin closed orbit vector”COn̂

s2AS

ring

makes one turn

stable polarizationS

if ║ COn̂


Challenge: Spin coherence time

Spin closed orbit

Challenge: Spin coherence time


We usually don‘t worry about coherence of spins along

At injection all spin vectors aligned (coherent)

After some time, spin vectors get out of phase and fully populate the cone

Polarization not affected!

Situation very different, when you deal with machines with frozen spin.

At injection all spin vectors aligned Later, spin vectors are out of phase in the horizontal plane

Longitudinal polarization vanishes!

COn̂

In an EDM machine with frozen spin, observation time is limited.

Challenge: SCT stimates (N.N. Nikolaev)


One source of spin coherence are random variations of the spin tune due to the momentum spread in the beam

and is randomized by e.g., electron cooling

Estimate:

𝛿𝜃=𝐺𝛿𝛾 𝛿𝛾cos𝜔𝑡→cos (𝜔𝑡+𝛿𝜃 )

𝜏𝑠𝑐 ≈1

𝑓 rev𝐺2 ⟨𝛿𝛾 2 ⟩

≈ 1𝑓 rev𝐺

2𝛾2 𝛽4 ⟨(𝛿𝑝𝑝 )2⟩

−1

𝑇 kin=100 MeV 𝑓 rev=0.5 MHz

𝜏𝑠𝑐 (𝑝 )≈3 ∙103 s 𝜏𝑠𝑐 (𝑑)≈5 ∙105 s

𝐺𝑝=1.79 𝐺𝑑=−0.14

Spin coherence time for deuterons may be × larger than for protons𝟏𝟎𝟎

EDM at COSY: COoler SYnchrotron

Cooler and storage ring for (polarized) protons and deuterons

Phase space cooled internal & extracted beams

Injector cyclotron

COSY

… the spin-physics machinefor hadron physics


… an ideal starting pointfor a srEDM search

Challenge: First measurement of SCT

Polarimetry:

Spin coherence time:


from Ed Stephensonand Greta Guidoboni

decoherencetime

oscillationcapture

5 s 25 s 5 s

2011 Test measurements at COSY

31

Challenge: SCT recent achievements


Result from 2012 run

Excellent progress towards the SCT goal for pEDM: s

from Ed Stephenson (Indiana)and Greta Guidoboni (Ferrara)


Challenge: Polarimetry

Beam polarimetry at ppm level achieved for deuteron beams

33

Outline






Precursor experiments: RF methods

Use existing magnetic machines for first direct EDM measurements

Method based on making spin precession in machine resonant with orbit motion

Two ways: 1. Use an RF device that operates on some harmonics of the spin

precession frequency

2. Operate ring on an imperfection resonance


Precursor experiments: 1. Resonance Method with „magic“ RF Wien filter

Avoids coherent betatron oscillations of beam. Radial RF-E and vertical RF-B fields to observe spin rotation due to EDM.Approach pursued for a first direct measurement at COSY.

„Magic RF Wien Filter“ no Lorentz force Indirect EDM effect

Observable:Accumulation of vertical polarization during spin coherence time

Polarimeter (dp elastic)

stored d

RF E(B)-field In-plane polarization

Statistical sensitivity for in the range to range possible.• Alignment and field stability of ring magnets• Imperfection of RF-E(B) flipper


Precursor experiments: 1. Resonance Method for deuterons at COSY Parameters: beam energy

assumed EDME-field

𝐭𝐮𝐫𝐧𝐧𝐮𝐦𝐛𝐞𝐫

𝑷 𝒙 𝑷 𝒛 𝑷 𝒚

EDM effect accumulates in


Parameters: beam energy assumed EDME-field


𝑃 𝑦

𝐭𝐮𝐫𝐧𝐧𝐮𝐦𝐛𝐞𝐫

𝑷 𝒚

Precursor experiments:1. Resonance Method for deuterons at COSY

Linear extrapolation of for a time period of yields a sizeable .

Search for permanent Electric Dipole Moments 38

Development: RF E/B-Flipper (RF Wien Filter)

[email protected]

1. Upgrade test flipper with electrostatic field plates ready end of year.2. Build lower power version using a stripline system3. Build high-power version of stripline system ( )

Work by S. Mey, R. Gebel (Jülich)J. Slim, D. Hölscher (IHF RWTH Aachen)


Precursor experiments:2. Resonanct EDM measurement with static Wien Filter

Machine operated on imperfection spin resonance at

𝑷𝒙(𝒕)

𝒕 (𝐬)Similar accumulation of EDM signal, systematics more difficult, strength of imperfection resonance must be suppressed by closed-orbit corrections.

Spin rotation in phase with orbit motion

without static WF

40

Outline






New EDM collaboration established

In 2012, JEDI collaboration founded (members)

Jülich Electric Dipole Moment Investigations

Spokespersons: Andreas Lehrach (Jülich)Jörg Pretz (RWTH Aachen)F.R. (Jülich)

[email protected]

May the force be with us!


Events in 2013

• JARA-FAME kick-off January 17, 2013 • new pillar of Jülich-Aachen Research Alliance• Samuel C. C. Ting on AMS-Experiment at ISS

• JEDI collaboration meeting March 13-14, 2013• Ferrara International School Niccolò Cabeo 2013

Physics beyond the standard model: The precision frontierMay, 20-24 2013, IUSS, Ferrara (Italy)

• Opportunities for Polarized Physics at FermilabMay 20-22, 2013, Fermilab, USA

[email protected]

43

Outline





Step Aim / Scientific goal Device / Tool Storage ring

1Spin coherence time studies Horizontal RF-B spin flipper COSY

Systematic error studies Vertical RF-B spin flipper COSY

2COSY upgrade Orbit control, magnets, … COSYFirst direct EDM measurement at RF-E(B) spin flipper Modified

COSY

3 Built dedicated all-in-one ring for , ,

Common magnetic-electrostatic deflectors

Dedicated ring

4 EDM measurement of , , at Dedicated ring


Timeline: Stepwise approach all-in-one machine for JEDI

Time scale: Steps 1 and 2: years (i.e., in POF 3)Steps 3 and 4: years

• Measurements of EDMs extremely difficult, but fantastic physics reach• Two storage ring projects, at BNL and Jülich

• BNL all-electric machine at magic momentum• Jülich goes for all-in-one machine concept (deuteron)

• Pursue SCT investigations at COSY• Very good prospects for first direct EDM measurements of and at

COSY using resonance methods based on RF E(B) –fields• New collaboration established: JEDI • Both collaborations work jointly on technological challenges:

Polarimetry, SCT, E-field generation, BPMs, etc• Strong need for high precision spin tracking tools, incl. RF structures• Begin electrostatic deflector development using FNAL equipment• JEDI: Ideas to converge by fall of 2013 POF 3 Evaluation


Conclusion

46

Georg Christoph Lichtenberg (1742-1799)

“Man muß etwas Neues machen, um etwas Neues zu sehen.”“You have to make (create) something new,

if you want to see something new”



Spares

[email protected]

48

N. Arkani-Hamed (IAS, Princeton) at Intensity Frontier WS, USA (2011)

Physics: Potential of EDMs


EDM searches – only upper limits yet (in )


Particle/Atom Current EDM Limit Future Goal equivalent

Electron

Neutron

Proton

Deuteron ?

Physics: Limits for Electric Dipole Moments

Huge efforts underway worldwide to improve limits / find EDMs

50

Physics beyond the Standard Model (BSM)

• CPV in the SM points to physics we do not understand

• CPV is highly sensitive to physics beyond the SM (New Physics)

• CPV is accessible to a wide range of experiments

• New source of CPV beyond the SM required for baryogenesis

EDMs: Why is CPV so interesting?


srEDM cooperations

Institutional (MoU) and Personal (Spokespersons …) Cooperation, Coordination

International srEDM Network

srEDM Collaboration (BNL)(spokesperson Yannis Semertzidis)

JEDI Collaboration (FZJ)(spokespersons: A. Lehrach, J. Pretz, F.R.)

Common R&DRHIC EDM-at-COSY

Beam Position Monitors Polarimetry (…) Spin Coherence Time

Cooling Spin Tracking (…)

DOE-Proposal (submitted)

Study Group

First direct measurement Ring Design

JEDI pEDM Ring at BNL

HGF Application(s) CD0, 1, …


52

Magnetic moment, spin, g and G


𝜇𝑁=𝑒 ∙ℏ

2 ∙𝑚𝑝=5.05078324 J T −1

Nuclear magneton

particle spin charge proton

deuteron3He

𝜇=𝑔 ∙𝜇𝑁 ∙𝑚𝑝

𝑚 ∙𝑍 ∙ 𝑠

Operation of „magic“ RF Wien filter


Radial E and vertical B fields oscillate, e.g., with (here ).

Spin coherence time may depend on excitation and on chosen harmonics

beam energy

Simulation of resonance Method with Magic Wien filter for deuterons at COSY

Linear extrapolation of for a time period of .


Parameters: beam energy assumed EDME-field


𝑃 𝑦

turn number


Why also EDMs of protons and deuterons?

Proton and deuteron EDM experiments may provide one order higher sensitivity.

In particular the deuteron may provide a much higher sensitivity than protons.

Consensus in the theoretical community:Essential to perform EDM measurements on different targets with similar sensitivity:

• unfold the underlying physics,• explain the baryogenesis.


Magic condition: Protons

Case 2: and fields

magic energy

𝐵>0 𝐵<0magic energy

𝐵>0 𝐵<0

Magic condition: Deuterons

and fields


Magic condition: Helions


and fields

Some polarimetry issuespC and dC polarimetry is the currently favored approach for the pEDM experiment at BNL


srEDM experiments use frozen spin mode, i.e., beam mostly polarized along direction of motion,

most promising ring options use cw & ccw beams.

• scattering on C destructive on beam and phase-space,• scattering on C determines polarization of mainly

particles with large betatron amplitudes, and• is not capable to determine . • For elastic scattering longitudinal analyzing powers are tiny (violates parity).

Ideally, use a method that would determine .

Exploit observables that depend on beam and target polarization


b eam1𝑃=(𝑃 𝑥

𝑃 𝑦𝑃 𝑧

)t arget (¿beam2)𝑄=(𝑄𝑥

𝑄𝑦𝑄𝑧

)

𝜎𝜎0

=1+𝐴𝑦 [ (𝑃 𝑦+𝑄𝑦 ) cos𝜑− (𝑃 𝑥+𝑄𝑥 ) sin 𝜑 ]

Spin-dependent differential cross section for

Analyzing powerSpin correlations

In scattering, necessary observables are well-known in the range MeV (not so for or ).

𝑥 (sideways)

𝑦 (up)

𝑧 (along beam)

𝜑

𝜃

How could one do that, determine ?

Suggestion 1: Use a polarized storage cell target


Detector

• Detector determines of cw & ccw beams separately, based on kinematics.• Alignment of target polarization along axes by magnetic fields. Leads to

unwanted MDM rotations absolute no-go in EDM experiments.

cell

CW CCW


Suggestion 2: Use colliding beam from external source

• Collide two external beams with cw and ccw stored beams.• Energy could be tuned to match detector acceptance.• Polarization components of probing low-energy beam can be made large, would

be selected by spin rotators in the transmission lines.• Luminosity estimates necessary

Detector

Polarized ion source(~10 MeV)


𝜎𝜎0

=1+𝐴𝑦 [ (𝑃 𝑦+𝑸𝒚 )cos𝜑− (𝑃𝑥+𝑸 𝒙 ) sin 𝜑 ]

cw beam𝑃=(𝑃 𝑥

𝑃 𝑦𝑃 𝑧

) probingbeam𝑄=(𝑄𝑥

𝑄𝑦𝑄𝑧

)=(𝑄𝑥

00 ) ,( 0

𝑄𝑦0 ) ,∨( 0

0𝑄𝑧

)



Suggestion 3: Use directly reactions from colliding beams

Detector

CW CCW

Requires luminosity, -functions at IP should be rather small.• Advantage over suggestion 2. is that supports luminosity.• Disadvantage is that sensitivity comes mainly from terms with and .• Detailed estimates necessary.

𝜎𝜎0

=1+𝐴𝑦 [ (𝑃 𝑦+𝑄𝑦 ) cos𝜑− (𝑃 𝑥+𝑄𝑥 ) sin 𝜑 ]

cw beam𝑃=(𝑃𝑥

𝑃𝑦𝑃𝑧

) ccw beam𝑄=(𝑄𝑥

𝑄𝑦𝑄𝑧

)

Luminosity estimate for the collider option


𝐿(𝑇 , 𝛽 )=𝑁1𝑁2 𝑓 rev(𝑇 )𝑛𝑏4𝜋 𝜎 (𝛽)2

𝜎 (𝛽)=√𝜖 ∙ 𝛽

Conditions:

k inetic energy(MeV )

Luminosity

𝛽=10 m

𝛽=1m

𝛽=0.1m

T magic=232.8 MeV

Even under these very optimistic assumptions, event rate will be rather low.


Symmetries

Parity:

[email protected]

𝑷 :(𝒙𝒚𝒛 )→(− 𝒙−𝒚− 𝒛 )

C-parity (or Charge parity): Changes sign of all quantized charges• electrical charge,• baryon number,• lepton number,• flavor charges, • Isospin (3rd-component)

T-Symmetry: 𝑻 :𝒕→− 𝒕

Physical laws are invariant under certain transformations.


New Idea: Ivan Koop‘s spin-wheel

[email protected]

B𝑑𝑆𝑑𝑡 =

𝑑×𝐸+𝜇×𝐵

By appropriate choice of magnetic field, the spin vector rotates fast frequencies of the order kHz

Jülich has expertise in SQUIDs, people say, state-of-the art measurements allow for is

(

This would revolutionize the way we conceive EDM (and in general polarization) experiments, because frequencies become directly measureable.


How this would work?

[email protected]

Frequency

B field

EDM=0

EDM ≠0

∼ ⟨Δ 𝑦 ⟩

Find the value of B wherespin precession frequency

disappears


SQUIDs: Precision tools for accelerators

[email protected]

Possible applications in accelerators, all of which are needed for srEDM experiments

1. Beam current transformers2. Beam position monitors3. Beam polarimeters

Begin development with a measurement of the noise spectrum using three coils:

• Coil 35mm away from center ANKE chamber

• Combined coils in same housing • GHz range (one pickup loop)• MHz range (several hundered loops)

• Fluxgate sensor • kHz range

Measurement of noise spectrum at COSY in MD week, July 2013


New Idea: Direct measurement of electron EDM

[email protected]

Bill Morse: , , (talk tomorrow)

Nobody knows where CPV is hiding, may well be in the leptonic sector

Needs a dedicated R&D effort

Very attractive:• Tests all ingredients of srEDM experiments• Could develop into a long-term project

Polarimetry is an issue

Goal:

Could be an option for FNAL using the electrostatic Tevatron separators


Projects and persons

Accelerator

Systematic error studies

[email protected]

Student Topic ResponsibleDenis Zyuzin Cosy-Infinity (final ring) Y. Senichev

Marcel Rosenthal Cosy-Infinity (COSY) A. Lehrach

Artem Saleev Cosy-Infinity Nikolaev/Rathmann

Andrea Pesce invariant spin axis P. Lenisa

Lorena Magallanes (M) Cosy-Infinity snake A. Lehrach

Stas Chekmenev Systematic error studies

J. Pretz

Search for permanent Electric Dipole Moments [email protected]

PolarimetryStudent Topic ResponsibleGreta Guidobini Data analysis P. Lenisa

Paul Maanen Polarimeter concepts J. Pretz

Dennis Eversmann (M) Data analysis J. Pretz

Fabian Hinder (M) Polarimeter J. Pretz

Sebastian Mey RF E/B flipper J. Pretz/ R. Gebel

Projects and persons

NN Magnetometer H. Soltner/H.-J. Krause

B field measurement

NN Electrostatic deflectors A. Nass/F. Rathmann

Electrostatic deflectors

RF E/B flipper

Documents

Search for permanent Electric Dipole Moments