3D-structure of nucleons from an EIC
D. Hasch
 the scientific case
 realisation & challenges
 projections for key
measurements
Acknowledgement: this presentation highly
profits from the EIC white paper (2012) & INT11-034 (2011) EIC science book
BNL-98815-2012-JA | JLAB-PHY-12-1652 | arXiv: 1212.1701
Workshop on the 3D-Structure of Nucleons & Nuclei
Como (Italy), 10-14 June 2013
nucleon structure: key questions
 rise of gluon distribution
gluon distribution
must saturate !
(unitarity bound)
nucleon structure: key questions
 rise of gluon distribution
 role of strangeness
nucleon structure: key questions
 rise of gluon distribution
 role of strangeness
 origin of spin:
role of sea quarks,
gluons & OAM
nucleon structure: key questions
 rise of gluon distribution
 role of strangeness
 origin of spin:
role of sea quarks,
gluons & OAM
 nucleon tomography:
3D imaging
spin-orbit correlations
multi-parton correlations
key questions & relevance
 rise of gluon distribution
 role of strangeness
 origin of spin:
role of sea quarks,
gluons & OAM
 nucleon tomography:
3D imaging
spin-orbit correlations
multi-parton correlations
to other fields
 necessary input for
calculations for hadron
colliders (Tevatron, LHC)
• higgs production
• beyond SM
key questions & relevance
 rise of gluon distribution
 role of strangeness
to other fields
 necessary input for
calculations for hadron
colliders (Tevatron, LHC)
• higgs production
• beyond SM
 origin of spin:
role of sea quarks,
gluons & OAM
 nucleon tomography:
3D imaging
spin-orbit correlations
multi-parton correlations
 indispensable for
quantitative analysis of
heavy-ion collision data
(RHIC, LHC)
key questions & relevance
 rise of gluon distribution
 role of strangeness
to other fields
 necessary input for
calculations for hadron
colliders (Tevatron, LHC)
• higgs production
• beyond SM
 origin of spin:
role of sea quarks,
gluons & OAM
 nucleon tomography:
3D imaging
spin-orbit correlations
multi-parton correlations
 indispensable for
quantitative analysis of
heavy-ion collision data
(RHIC, LHC)
call for a new facility: polarised Electron-Ion Collider
science case of an EIC
2007
“An EIC with polarized beams
has been embraced by the U.S.
nuclear science community as
embodying the vision for
reaching the next QCD
frontier.”
science case of an EIC
‘science book’ of an EIC: INT-11-034, arXiv: 1108.1713 [based on INT workshop Sep-Nov 2010]
‘EIC white paper’: BNL-98815-2012-JA, JLAB-PHY-121652, arXiv: 1212.1701
 spin & flavour structure of the nucleon
 3D-structure of nucleons & nuclei in momtum and
configuration space
 QCD matter in nuclei
 luminosity frontier: EW physics & search for physics
beyond the SM
science case of an EIC
‘science book’ of an EIC: INT-11-034, arXiv: 1108.1713 [based on INT workshop Sep-Nov 2010]
‘EIC white paper’: BNL-98815-2012-JA, JLAB-PHY-121652, arXiv: 1212.1701
 spin & flavour structure of the nucleon
 3D-structure of nucleons & nuclei in momtum and
configuration space
 QCD matter in nuclei
 EW physics & search for physics beyond the SM
science case of an EIC
‘science book’ of an EIC: INT-11-034, arXiv: 1108.1713 [based on INT workshop Sep-Nov 2010]
‘EIC white paper’: BNL-98815-2012-JA, JLAB-PHY-121652, arXiv: 1212.1701
 spin & flavour structure of the nucleon
 3D-structure of nucleons & nuclei in momtum and
configuration space
 QCD matter in nuclei
 luminosity frontier: EW physics & search for physics
beyond the SM
& other
surprises …
landscape of high energy leptonnucleon facilities
Luminosity(*1030/cm2/s)
 existing facilities [ongoing data analysis]
109
108
107
106
105
104
JLab
103
102
101
HERMES
HERA-collider
COMPASS
1
10
100 CM energy (GeV)
landscape of high energy leptonnucleon facilities
Luminosity(*1030/cm2/s)
 existing facilities [ongoing data analysis]
 upcoming facilities
 JLAb12 : detailed study of 3D nucleon
structure in ‘valence kinematic region’
 COMPASS-II : complementary & wide
kinematic range
109
108
107
106
105
104
JLab@12GeV
JLab
107
103
102
101
HERMES
1
COMPASS-II
COMPASS
10
HERA-collider
100 CM energy (GeV)
landscape of high energy leptonnucleon facilities
Luminosity(*1030/cm2/s)
 existing facilities [ongoing data analysis]
 upcoming facilities
 >2020 future facilities
 JLAb12 : detailed study of 3D nucleon
structure in ‘valence kinematic region’
 COMPASS-II : complementary & wide
kinematic range
109
108
107
106
105
104
JLab@12GeV
 EIC : ‘gold rush’ for exploration of
nucleon structure & beyond
JLab
realisation options:
107
103
102
101
MEIC
ELIC
ENC
HERMES
1
COMPASS-II
COMPASS
10
eRHIC @BNL
MEIC/ELIC @Jlab
eRHIC
LHeC
HERA-collider
100 CM energy (GeV)
ENC @FAIR
LHeC @ CERN
kinematic landscape
-- semi-inclusive DIS -[example: existing measurements for Sivers asymmetry & EIC kinematic reach]
√s = 18 GeV
√s = 7 GeV
√s = 5 GeV
√s = 3 GeV
kinematic landscape
-- hard exclusive reactions -[example: existing measurements of DVCS and EIC kinematic reach]
EIC: high energy & high luminosity
-- energy / luminosity landscape -example: estimates of peak luminosity for eRHIC
*1033
SIDIS @EIC: wide x-Q2 coverage
-- anticipated 30 days data taking [@eRHIC] -5 x 50 GeV
10 x 100 GeV
4 fb-1
13 fb-1
20 x 250 GeV
30 x 325 GeV
20 fb-1
4 fb-1
y = 0.05
10-5
y = 0.005
10-1
EIC facility
-- projects world wide under R&D --
4 sites @existing facilities under study:
 eRHIC @BNL: add linear e accelerator to existing RHIC
 MEIC/ELIC @JLab: add e & A storage rings to existing CEBAF
 ENC @FAIR: add linear e accelerator to planned HESR
 LHeC @LHC: add e accelerator to existing LHC (NO polarization)
EIC facility
-- projects world wide under R&D --
peak luminosity [cm-2s-1]
4 sites @existing facilities under study:
ECM [GeV]
EIC @BNL or JLab
-- technology frontiers -general characteristics:

highly polarized (> 70%) electron, proton & 3He beams

ion beams from deuterium to heaviest nuclei – uranium or lead

variable center of mass energies s = 20 – 150 GeV

high luminosity ~1034 cm2/s

staged designs with first stage up to s ~ 70 GeV
EIC @BNL or JLab
-- technical challenges -significant R&D required for realisation
EIC @BNL or JLab
-- technical challenges -significant R&D required for realisation – high luminosity :

“crab waist” crossing  new for hadron beams (used @super-B factories)
o
high luminosity machines use angle crossing to avoid more
than one bunch-bunch collision
 causes usually lumi loss  Palmer 1988: RF deflects front
You look in one direction
and walk in another one ...
and back of bunches in opposite ways  head-on
collisions even with angle crossed beams:
EIC @BNL or JLab
-- technical challenges -significant R&D required for realisation – high luminosity :

“crab waist” crossing  new for hadron beams (used @super-B factories)

ERL : energy recovering linear collider  new for high energies
o
super-conductive cavities for permanent
operation: 2 loop passing for acceleration &
deceleration
o
oscillations in undulator (set of horse-shoe
magnets) causes X-ray & tiny energy loss BUT
major part of energy recaptured in elm fields 
ready for next acceleration turn
o
# of cavities determines the el energy
EIC @BNL or JLab
-- technical challenges -significant R&D required for realisation – high luminosity :

“crab waist” crossing  new for hadron beams (used @super-B factories)

ERL : energy recovering linear collider  new for high energies

new technique of coherent electron cooling of hadron beams using FEL [@BNL]
(standard electron cooling @JLab)
o
o
ions pass monochromatic cold e- beam (plasma)
interaction with induced electric field of co-streaming e energy kicks towards their central energy value
o proof-of-principle experiment for CeC @BNL in 2015
EIC @BNL or JLab
-- technical challenges -significant R&D required for realisation – high luminosity :

“crab waist” crossing  new for hadron beams (used @super-B factories)

ERL : energy recovering linear collider  new for high energies

new technique of coherent electron cooling of hadron beams using FEL [@BNL]
(standard electron cooling @JLab)

BNL: highly polarized e- source of 10x currently available intensities
o
novel “super-lattice” GaAs cathodes
gatling (‘revolver’) photo-gun
 combining currents from multiple guns
E
EIC @BNL or JLab
-- technical challenges -significant R&D required for realisation – high luminosity :

“crab waist” crossing  new for hadron beams (used @super-B factories)

ERL : energy recovering linear collider  new for high energies

new technique of coherent electron cooling of hadron beams using FEL [@BNL]
(standard electron cooling @JLab)

BNL: highly polarised e- source of 10x currently available intensities
EIC @BNL or JLab
-- technical challenges -significant R&D required for realisation – high luminosity & polarisation :

“crab waist” crossing  new for hadron beams (used @super-B factories)

ERL : energy recovering linear collider  new for high energies

new technique of coherent electron cooling of hadron beams using FEL [@BNL]
(standard electron cooling @JLab)

BNL: highly polarised e- source of 10x currently available intensities

MEIC/ELIC: novel figure-8 storage rings (twisted spin dynamics) for both e & A
 optimum for polarised ion beams:
Siberian
snakes
RF
spin
rotators
o
preserve polarisation by avoiding
depol resonances
o
energy independence of spin
tune
o
only practical way to
accommodate polarised D
EIC @BNL or JLab
-- technical challenges -significant R&D required for realisation – high luminosity & polarisation :

“crab waist” crossing  new for hadron beams (used @super-B factories)

ERL : energy recovering linear collider  new for high energies

new technique of coherent electron cooling of hadron beams using FEL [@BNL]
(standard electron cooling @JLab)

BNL: highly polarised e- source of 10x currently available intensities

MEIC/ELIC: novel figure-8 storage rings (twisted spin dynamics) for both e & A
staged options @JLab:
enlarge both figure-8 rings
e- from 12GeV CEBAF
EIC @BNL or JLab
-- technical challenges -significant R&D required for realisation – high luminosity & polarisation :

“crab waist” crossing  new for hadron beams (used @super-B factories)

ERL : energy recovering linear collider  new for high energies

new technique of coherent electron cooling of hadron beams using FEL [@BNL]
(standard electron cooling @JLab)

BNL: highly polarised e- source of 10x currently available intensities

MEIC/ELIC: novel figure-8 storage rings (twisted spin dynamics) for both e & A
Ce-cooling
staged options @BNL:
PHENIX
main ERL (2 GeV per pass)
STAR
four e-beam passes
increase e- beam energy from 530 GeV by building up the ERLINAC
EIC @BNL or JLab
-- technical challenges -significant R&D required for realisation – high luminosity & polarisation :

“crab waist” crossing  new for hadron beams (used @super-B factories)

ERL : energy recovering linear collider  new for high energies

new technique of coherent electron cooling of hadron beams using FEL [@BNL]
(standard electron cooling @JLab)

BNL: highly polarised e- source of 10x currently available intensities

MEIC/ELIC: novel figure-8 storage rings (twisted spin dynamics) for both e & A
R&D for next 5-8 years
EIC @BNL or JLab
-- status of machine design @POETIC2013 -V. Litvinenko:
 eRHIC design progresses well:
 Design is completed and went through the External Review
 Cost estimate is underway with two cost-effective designs
 Phase I eRHIC can be built for about $550M (excluding the detector)

Physics of the collider is well understood:
 No show-stoppers were found
 R&D is under way.
 In few years we will complete R&D and will be ready for eRHIC construction.
Y. Derbenev:
• The MEIC concept has been stable for 3 years
– Allowing for refinement of the design
– MEIC design report completed and available on the arXiv: 1209.0757
– Phased options including use of 25 GeV booster under consideration
– Some accelerator R&D funds have been allocated
– Joint detector R&D projects have started
• The MEIC design is based predominantly on proven technology & our
immediate goal is full validation of the MEIC design with R&D
EIC detector design
general concept driven by:
o
o
o
o
acceptance & resolution for envisaged physics
design of IP (crossing angles, magnet locations, ecc.)
background conditions (sync. radiation)
minimising systematic uncertainties (polarimetry, luminosity measur.)
EIC detector design
general concept driven by:
o
o
o
o
acceptance & resolution for envisaged physics
design of IP (crossing angles, magnet locations, ecc.)
background conditions (sync. radiation)
minimising systematic uncertainties (polarimetry, luminosity measur.)
example: detection of the remaining baryonic state closely connected with IP design:
very forward
ion beam
direction
EIC detector design
general concept  requirements from physics reactions:
Inclusive DIS reactions: Dg, helicity PDFs from g1, FL, ...
o very good e’ ID with excellent momentum and angular resolution
 DIS kinematics from s catterred lepton
o hadronic calorimetry (jets)
EIC detector design
general concept  requirements from physics reactions:
Inclusive DIS reactions: Dg, helicity PDFs from g1, FL, ...
o very good e’ ID with excellent momentum and angular resolution
 DIS kinematics from s catterred lepton
o hadronic calorimetry (jets)
Semi-inclusive DIS reactions: TMDs, hadron production, ...
o excellent particle ID: p±,K±, p±
o full f coverage around g*
o excellent vertex resolution  charm, bottom ID
EIC detector design
general concept  requirements from physics reactions:
Inclusive DIS reactions: Dg, helicity PDFs from g1, FL, ...
o very good e’ ID with excellent momentum and angular resolution
 DIS kinematics from s catterred lepton
o hadronic calorimetry (jets)
Semi-inclusive DIS reactions: TMDs, hadron production, ...
o excellent particle ID: p±,K±, p±
o full f coverage around g*
o excellent vertex resolution  charm, bottom ID
exclusive reactions: GPDs, nucleon/nuclei imaging, ...
Q2
o exclusivity : full acceptance detectors
o forward detection of recoil baryons
o m (J/Y) and g (DVCS, p0) detection
 most stringend demands
t
EIC detector design
general concept  requirements from physics reactions:
Inclusive DIS reactions: Dg, helicity PDFs from g1, FL, ...
o very good e’ ID with excellent momentum and angular resolution
 DIS kinematics from s catterred lepton
o hadronic calorimetry (jets)
Semi-inclusive DIS reactions: TMDs, hadron production, ...
o excellent particle ID: p±,K±, p±
o full f coverage around g*
o excellent vertex resolution  charm, bottom ID
exclusive reactions: GPDs, nucleon/nuclei imaging, ...
Q2
o exclusivity : full acceptance detectors
o forward detection of recoil baryons
o m (J/Y) and g (DVCS, p0) detection
 most stringend demands
t
high luminosity  excellent control of systematic uncertainties
EIC detector design
emerging principle detector concept: eRHIC detector
(nearly) hermetic central detector:
p, A
e
EIC detector design
emerging principle detector concept: MEIC detector
(nearly) hermetic central detector:
p, A
e
EIC detector design
emerging principle detector concept & IP - the challenges:
o crossing angle @IP
o hermetic detector with high resolution & particle ID
o small angle coverage
[eRHIC design
as example…]
EIC detector design
emerging detector concept & IP - the challenges:
o crossing angle @IP
o hermetic detector with high resolution & particle ID
o small angle coverage
ZDC
FPD
FED
ZDC: zero degree
calo: neutron det.
FPD: forward
protron det.
FED: forward
electron det.
[eRHIC design
as example…]
EIC detector design
emerging detector concept & IP - the challenges:
o crossing angle @IP
o hermetic detector with high resolution & particle ID
solenoid
hadronic calo
elm. calorimeter
multi radiator RICH
aerogel RICH
tracking
vertex tracking
+ polarimetry
+ lumi detectors
[eRHIC design
as example…]
EIC: design and R&D is on track
**** many technological challenges ****
 prove of principle
R&D ongoing and (largely) financed
EIC: 3D nucleon
structure
-- a few projections --
EIC: gluon polarisation
-- from scaling violation of g1 --
EIC: gluon polarisation
-- from scaling violation of g1 --
EIC: gluon polarisation
-- from scaling violation of g1 --
EIC: mapping of TMDs
-- going fully differential over a wide kinematic range --
10 fb-1
EIC: mapping of TMDs
-- going fully differential over a wide kinematic range --
unique:
o test TMD evolution
o access to sea quark and gluon TMDs
EIC: mapping of TMDs
-- going fully differential over a wide kinematic range --
unique:
o test TMD evolution
o access to sea quark and gluon TMDs
o test transition from low  high pT
EIC: mapping of TMDs
-- going fully differential over a wide kinematic range --
unique:
o test TMD evolution
o access to sea quark and gluon TMDs
o test transition from low  high pT
PhT = 1GeV
high luminosity demand: 120 fb-1
PhT = 4GeV
EIC: spatial imaging of partons
DVCS count
rates (BH
subtracted)
EIC: spatial imaging of partons
DVCS count
rates (BH
subtracted)
Q2 evolution 
mapping of GPDs:
EIC: spatial imaging of partons
DVCS count
rates (BH
subtracted)
10 fb-1
100 fb-1
EIC: spatial imaging of partons
DVCS count
rates (BH
subtracted)
EIC: spatial imaging of partons
DVCS count
rates (BH
subtracted)
clean access to gluon imaging from J/Y production
summary :
call for a new facility: EIC
-- worldwide first polarised Electron Nucleon / Ion Collider --
till today we have just understood
the tip of the iceberg
to understand nucleon structure
in terms of quark & gluon
degrees of freedom
you are here
q
q
g
summary :
call for a new facility: EIC
-- worldwide first polarised Electron Nucleon / Ion Collider --
till today we have just understood
the tip of the iceberg
to understand nucleon structure
in terms of quark & gluon
degrees of freedom
you are here
q
q
g
Ds
Dg
EIC will provide answers
to many
of our questions
& beyond
Lq,g
spin
sum rule
EIC highlights on nucleon structure
Inclusive DIS
SIDIS & TMDs
EIC highlights on nucleon structure
hard exclusive reactions
additional info
Science reach as fct of ECM & Lumi
Main Accelerator Challenges
In red –increase/reduction beyond the state of the art
ENC at FAIR
ELIC at JLaB
eRHIC at BNL
β*=0.5 cm
50x reduction
Polarized electron gun –
50x increase
Depolarization at the top
energy
Polarized e- source
8 MV, 3 A magnetized
electrostatic
(Voltage*2, Current*6)
HE Electron Cooling –
100x increase in the rate
of cooling
Coherent Electron
Cooling – New concept
Energy reach beyond 70
GeV for leptons
Potential 10x gains from
cooling, but need special
CeC
Investigation of large
beam-beam tune shift in
space charge dominated
regimes
High current recirculating
ring with ERL-injector
New concept
Multi-pass SRF ERL
5x increase in current
30x increase in energy
Synchrotron radiation
losses in the arcs
Multi-pass SRF ERL
5x increase in current
30x increase in energy
3-4x in # of passes
Crab crossing
(compliance with
acceptance of PANDA)
Crab crossing
5x the angle
New for hadrons
Crab crossing
New for hadrons
Crab crossing
New for hadrons
Crab crossing
New for hadrons
By-passes
Totally new tunnel
Complexity of the
sharing tunnel with LHC
Very challenging to have
e+ source
Polarized 3He production
LHeC at CERN
Ring-Ring
Linac-Ring
Limited space for electron
ring
Never explored beambeam parameter range
3-4x in ξ
Understanding of beambeam affects
New type of collider
Polarization life time in
electron ring
(lattice considerations)
Dispersive crab crossing
Traveling focus
New concepts
β*=5 cm
5x reduction
Space charge limits
beam dynamics,
Bunching (1200)
Sub-nsec kicker with
MHz rep-rate
50x shorter pulses
Multi-pass SRF ERL
3-4x in # of passes
Need new injector
Figure-8 ring spin
dynamics
New concept
Feedback for kink
instability suppression
Novel concept
Synchrotron radiation in
the IR
Using crossing angle to
avoid SR in IR
V.N. Litvinenko, IPAC’11, Kyoto, May 26, 2010
Four Electron-Ion Collider Facilities Considered
eRHIC
ELIC Electron
e-cooling
(RHIC II)
Cooling
IR
PHENIX
IR
Main ERL (2 GeV per pass)
Snake
STAR
ENC
Add electron
beam (COSY ring)
to GSI/HESR
[Rolf Ent, Trento Okt.08]
Four e-beam
passes
LHeC
Snake
BNL: eRHIC
Jlab: MEIC / ELIC
for more details:
•
LHeC web site http://cern.ch/lhec
•
LHeC CDR, J.Phys.G:Nucl.Part.Phys. 39, 075001 (2012)
•
ICFA Beam Dynamics Newsletter No. 58, special issue on future
electron-hadron colliders, August 2012