Mit
glie
d d
er
Helm
holt
z-G
em
ein
sch
aft
EDM Searches in storage rings
June 26, 2012 Frank Rathmann
on behalf of the BNL-EDM and JEDI collaborations
Workshop on existing and future Projects PNPI-Jülich 24-28 June 2012. Gatchina
Topics
Why EDMs? Search for EDMs using storage rings Two projects, at BNL and Jülich Spin coherence time First direct measurement
Resonance Method with RF E(B) -fields
Summary
2EDM Searches in storage rings [email protected]
What caused the Baryon asymmetry?
[email protected] EDM Searches in storage rings 3
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
Carina Nebula: Largest-seen star-birth regions in the galaxy
Observed 610-10WMAP+COBE (2003)
SM expectation ~10-18
nnn BB /)(
Permanent EDMs violate parity P and time reversal symmetry T
Assuming CPT to hold, combined symmetry CP violated as well.
Electric Dipole Moments (EDMs)
[email protected] 4EDM Searches in storage rings
EDMs are candidates to solve mystery of matter-antimatter asymmetry may explain why we are here!
History of neutron EDM limits
[email protected] EDM Searches in storage rings 5
Adopted from K. Kirch
• Smith, Purcell, Ramsey PR 108, 120 (1957)
• RAL-Sussex-ILL(dn 2.9 10-26 ecm) PRL 97,131801 (2006)
Sensitivity to NEW PHYSICS beyond the Standard Model
EDM searches - only upper limits up to now (in ecm):
Huge efforts underway to improve limits / find EDMs
[email protected] 6EDM Searches in storage rings
Limits for Electric Dipole Moments
485. WE-Heraeus-Seminar (July 0406, 2011) Search for Electric Dipole Moments (EDMs) at Storage Rings
http://www2.fz-juelich.de/ikp/edm/en/
Particle/Atom Current EDM Limit Future Goal dn equivalent
Neutron 3 10-26 10-28 10-28
199Hg 3.1 10-29 10-29 10-26
129Xe 6 10-27 10-30 – 10-33 10-26 – 10-29
Proton 7.9 10-25 10-29 10-29
Deuteron ? 10-29 3 10-29 – 5 10-31
[email protected] EDM Searches in storage rings 7
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 (p, d, 3He) with similar sensitivity:•unfold the underlying physics,•explain the baryogenesis.
NEW: EDM search in time development of spin in a storage ring:
“Freeze“ horizontal spin precession; watchfor development of a vertical component !
[email protected] 8EDM Searches in storage rings
Search for Electric Dipole Moments
0G
Edt
s
d
d
The frozen spin Method
[email protected] 9EDM Searches in storage rings
For transverse electric and magnetic fields in a ring ( ),anomalous spin precession is described by
0 EB
c
E
p
mGBG
m
qG
2
Magic condition: Spin along momentum vector
1. For any sign of G, in a combined electric and magnetic machine
2. For G>0 (protons) in an all electric ring
2
2gG
222
2
1
GBcG
GBcE
x
G
mp
p
mG
0
2
c
MeV74.700 (magic)
Magic condition: Protons
E-field only
10EDM Searches in storage rings [email protected]
5 10 15 20 25 30 350
20
40
60
80
100
Proton 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
Magic condition: Deuterons
E and B fields
11EDM Searches in storage rings [email protected]
100 200 300 400 5000
10
20
B=0.1 TB=0.2 TB=0.3 T
Deuteron EDM
kinetic energy (MeV)
radi
us (
m)
100 200 300 400 50015
10
5
0
B=0.1 TB=0.2 TB=0.3 T
Deuteron EDM
kinetic energy (MeV)
radi
al E
-fie
ld (
MV
/m)
Magic condition: Helions
E and B fields
12EDM Searches in storage rings [email protected]
100 200 300 400 5000
10
20
B=0.05 TB=0.1 TB=0.15 T
Helion EDM
kinetic energy (MeV)
radi
us (
m)
100 200 300 400 5000
10
20
30
B=0.05 TB=0.1 TB=0.15 T
Helion EDM
kinetic energy (MeV)
radi
al E
-fie
ld (
MV
/m)
NEW: EDM search in time development of spin in a storage ring:
A magic storage ring for protons (electrostatic), deuterons, …
“Freeze“ horizontal spin precession; watchfor development of a vertical component !
[email protected] 13EDM Searches in storage rings
Search for Electric Dipole Moments
particle p (GeV/c) E (MV/m) B (T)
proton 0.701 16.789 0.000
deuteron 1.000 -3.983 0.160
3He 1.285 17.158 -0.051
One machine with r ~ 30 m
0G
Edt
s
d
d
Two storage ring projects being pursued
(from R. Talman) (from A. Lehrach)
[email protected] 14EDM Searches in storage rings
BNL for protons all electric machine Jülich, focus on deuterons, or a combined machine
CW and CCW propagating beams
2 beams simultaneously rotating in a ring (CW, CCW)
Approved BNL-ProposalSubmitted to DOEGoal for protons
Technological challenges !
Carry out proof of principle experiments (demonstrators) at COSY
• Spin coherence time (1000 s)• Beam positioning (10 nm)• Continuous polarimetry (< 1ppm)• E - field gradients (~ 17MV/m at 2 cm)
Circumference~ 200 m
[email protected] 15EDM Searches in storage rings
BNL Proposal
year)(onecme105.2 29 pd
EDM at COSY – COoler SYnchrotron
Cooler and storage ring for (polarized) protons and deuterons
p = 0.3 – 3.7 GeV/c
Phase space cooled internal & extracted beams
Injector cyclotron
COSY
… the spin-physics machinefor hadron physics
[email protected] 16EDM Searches in storage rings
EDM at COSY – COoler SYnchrotron
Cooler and storage ring for (polarized) protons and deuterons
p = 0.3 – 3.7 GeV/c
Phase space cooled internal & extracted beams
Injector cyclotron
COSY
… an ideal starting pointfor a srEDM search
[email protected] 17EDM Searches in storage rings
A
AS
one particle with magnetic moment
“spin tune”
“spin closed orbit vector”COn̂
s2AS
ring
makes one turn
stable polarizationS
if ║ COn̂
[email protected] 18EDM Searches in storage rings
Spin closed orbit
Spin coherence
[email protected] EDM Searches in storage rings 19
We usually don‘t worry about coherence of spins along COn̂
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 S
COn̂
At injection all spin vectors aligned After some time, the spin vectors are all out of phase and in the horizontal plane
Longitudinal polarization vanishes!
COn̂
In an EDM machine with frozen spin, observation time is limited.
Estimate of spin coherence times (N.N. Nikolaev)
[email protected] EDM Searches in storage rings 20
One source of spin coherence are random variations of the spin tune due to the momentum spread in the beam
G and is randomized by e.g., electron cooling
)cos()cos( tt12
42222
11
p
p
vGfGf revrev
sc
MHz5.0revfMeV100kinT
s105)( 5dscs103)( 3psc
Estimate:
Spin coherence time for deuterons may be ~100 larger than for protons
14.0dG79.1pG
First measurement of spin coherence time
Polarimetry:
Spin coherence time:
[email protected] 21EDM Searches in storage rings
from Ed Stephensonand Greta Guidoboni
decoherencetime
oscillationcapture
5 s 25 s 5 s
2011 Test measurements at COSY
[email protected] EDM Searches in storage rings 22
Resonance Method with RF E-fields
Polarimeter (dp elastic)
stored d
RF E-fieldvertical
polarization
spin precession governed by: (* rest frame)
Two situations:
1. B*=0 By = ER (= 70 G for ER=30 kV/cm) EDM effect2. E*=0 ER = - By no EDM effect
5101/1000 ss
growsPP
dropsP
zx
y
22
[email protected] EDM Searches in storage rings 23
Simulation of resonance Method with RF E-fields for deuterons at COSY
Parameters: beam energy Td=50 MeV LRF=1 massumed EDM dd=10-20 ecmE-field 10 kV/cm
Constant E-field
Number of turns
E-field reversed every -/(G) 21 turns
Number of turns
[email protected] EDM Searches in storage rings 24
Simulation of resonance Method with RF E-fields for deuterons at COSY
Parameters: beam energy Td=50 MeVassumed EDM dd=10-20 ecmE-field 10 kV/cm
Linear extrapolation of for a time period of sc=1000 s (=3.7108 turns)
Number of turns
EDM effect accumulates
Polarimeter determines Px, Py and Pz
22zx PPP
[email protected] EDM Searches in storage rings 25
Resonance Method with „magic“ Wien filter
Approach pursued for a first direct measurement at COSY.Avoids transverse motion of beam in RF device! Radial RF-E and vertical RF-B fields to observe spin rotation due to EDM
E*=0 ER = - By „Magic RF Wien Filter“ no Lorentz force
Statistical sensitivity for dd in the range 10-23 to 10-24 ecm range possibleAlignment and field stability of ring magnetsImperfection of RF-E(B) flipper
„Indirect“ EDM effect
Tilt of precession plane due to EDM
Observable:Accumulation of vertical polarization during spin coherence timePolarimeter (dp elastic)
stored d
RF E(B)-fieldTransverse polarization
Operation of „magic“ Wien filter
[email protected] EDM Searches in storage rings 26
Spin coherence time may depend on excitation and on chosen harmonics
[email protected] EDM Searches in storage rings 27
Simulation of resonance Method with Magic Wien filter for deuterons at COSY
Parameters: beam energy Td=50 MeV LRF=1 massumed EDM dd=10-24 ecmE-field 30 kV/cm
Linear extrapolation of for a time period of sc=1000 s (=3.7108 turns)
EDM effect accumulates in Py
yP
[email protected] EDM Searches in storage rings 28
Simulation of resonance Method with Magic Wien filter for deuterons at COSY
Linear extrapolation of for a time period of sc=1000 s (=3.7108 turns)yP
EDM effect accumulates in Py
Parameters: beam energy Td=50 MeV LRF=1 massumed EDM dd=10-24 ecmE-field 30 kV/cm
Simulation of resonance Method with Magic Wien filter for deuterons at COSY
Linear extrapolation of for a time period of sc=100000 s (=3.71010 turns)yP
[email protected] EDM Searches in storage rings 29
EDM effect accumulates in Py
Parameters: beam energy Td=50 MeV LRF=1 massumed EDM dd=10-24 ecmE-field 30 kV/cm
Two years R&D/preparation
One year final ring design
Two years ring/beam-line construction
Two years installation
One year “string test”
12 13 14 15 16 17 18 19 20 21
Technically driven timeline for pEDM at BNL
[email protected] EDM Searches in storage rings 30
Stepwise approach in the JEDI project
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
2
COSY upgrade Orbit control, magnets, … COSY
First direct EDM measurement at 10-24 ecm
RF-E(B) spin flipperModified COSY
3Built dedicated all-in-one ring for p, d, 3He
Common magnetic-electrostatic deflectors
Dedicated ring
4EDM measurement of p, d, 3He at at 10-29 ecm
Dedicated ring
[email protected] EDM Searches in storage rings 31
Time scale: Steps 1 and 2: < 5 yearsSteps 3 and 4: > 5 years
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, …
[email protected] 32EDM Searches in storage rings
EDM Workshop at ECT* (Trento)
[email protected] 33EDM Searches in storage rings
October 1-5, 2012
Organizing committee
Jülich Hans Ströher [email protected] Rathmann [email protected] Wirzba [email protected]
BrookhavenMei Bai [email protected] Marciano [email protected] Semertzidis [email protected]
http://www.ectstar.eu/
• Measurement of EDMs extremely difficult, but the physics is fantastic!
• Two storage ring projects, at BNL and Jülich
• Pursue spin coherence time measurements at COSY
• First direct measurement at COSYResonance Method with RF E(B) -fields
• New JEDI collaboration established
[email protected] EDM Searches in storage rings 34
Summary
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”
[email protected] 35EDM Searches in storage rings
[email protected] 36EDM Searches in storage rings
Spare transparencies
[email protected] EDM Searches in storage rings 37
The ScientificFrontiers
to address well-defined questions
about the physicsof our World
EnergyIntensity
Precision
Cos
mic
Complexity
Mass (Higgs)Supersymmetry
Extra Dimensions
Symmetries(TRV, EDM)
Cosmic ParticlesDark MatterDark Energy
Stability (p-decay)Neutrino physics
CKM
LHCSuper-beam
Factories
DedicatedSmall-scale
Facilities
Mass
Matter Materials RHIC
QGP
QCD phase diagram
UndergroundLabs,Non-
accelerator
Mega-tonDetectors
Radiation Facilities
[email protected] EDM Searches in storage rings 38
COSY: Concept for Snake
• Should allow for flexible use at two locations
• Fast ramping (< 30s), with injection of Py
• Cryogen-free system
• Should be available in 2012
Bdl (Tm)
pn→{pp}sπ- at 353 MeV 3.329
PAX at COSY 140 MeV 1.994
PAX at AD 500 MeV 4.090
Tmax at COSY 2.88 GeV 13.887
ANKE
PAXPAX
ANKE
[email protected] EDM Searches in storage rings 39
One backup slide for olrov
spin manipulation
there is an for every point of the orbitSnakes (non-vertical B field) affect
snakesCOn̂
COn̂
flippersramping through a resonance reverses COn̂
spin closed orbit
180o
[email protected] 40EDM Searches in storage rings
Machine acceptance
[email protected] EDM Searches in storage rings 41
lost
cooled
targetring acceptance
beam
In an ideal machine (like TSR-HD)→ Single-Coulomb scattering at
the target dominates beam loss
K. Grigoriev et al., NIMA 599,130 (2009)
[email protected] EDM Searches in storage rings 42
Future: Time Reversal Invariance Test
COSY-TRIC: P-even, T-odd
Total polarization correlation coefficient Ay,xz leads to relative difference of current slopes
Milestone: Operation of Precision BCT with I/I<10-4
IBeam
time
COSY used as accelerator and detector:
PAX
Need for a high precision BCT
[email protected] EDM Searches in storage rings 43
Status TRI Test at COSY
• Slow fluctuations in the measured BCT signal exceed the noise band at higher frequencies
Possible solution:Cryogenic Current Comparator, read out by low-temperature super-conducting quantum interference device
Highest resolution achieved: 250 pA/Hz
A. Steppke, IEEE Trans. Appl. Superc. (2009)
D. Eversheim Hyperfine Interact 193 (2009)
Freezing Spin Precession with E-Fields
11
01
12
G
G
G > 0 for γ > 1, if only electric fields are applied
Magic momentum for protons: p = 700.74 MeV/c
G
mp
G 1
1
μp / μN = 2.792 847 356 (23) Gp = 1.7928473565μd / μN = 0.857 438 2308 (72) Gd = -0.14298727202μHe-3 / μN = -2.127 497 718 (25) G3He= -4.1839627399
Nuclear magneton: μN = eħ / (2mpc) = 5.050 783 24 (13) · 10-27 J T-1
[email protected] 44EDM Searches in storage rings