1. EIC Detector Overview Tanja Horn Tanja Horn, EIC Detector Overview, EIC Advisory Committee 2011 Electron-Ion Collider Advisory Committee, Jefferson Laboratory, Newport News, VA 10 April 2011 1

2. Science of an EIC: Explore and Understand QCD Tanja Horn, EIC Detector Overview, EIC Advisory Committee 2011 2 Map the spin and spatial quark-gluon structure of nucleons ̶ Image the 3D spatial distributions of gluons and sea quarks through exclusive J/ Ψ, γ (DVCS) and meson production ̶ Measure Δ G, and the polarization of the sea quarks through SIDIS, g1, and open charm production ̶ Establish the orbital motion of quarks and gluons through transverse momentum dependent observables in SIDIS and jet production Discover collective effects of gluons in nuclei ̶ Explore the nuclear gluon density and coherence in shadowing through e + A → e‘ + X and e + A → e‘ + cc + X ̶ Discover novel signatures of dynamics of strong color fields in nuclei at high energies in e + A → e’ + X(A) and e + A → e’ + hadrons + X ̶ Measure gluon/quark radii of nuclei through coherent scattering γ * + A → J/ Ψ + A Understand the emergence of hadronic matter from quarks and gluons −Explore the interaction of color charges with matter (energy loss, flavor dependence, color transparency) through hadronization in nuclei in e + A → e' + hadrons + X −Understand the conversion of quarks and gluons to hadrons through fragmentation of correlated quarks and gluons and breakup in e + p → e' + hadron + hadron + X [INT 2010]

3. C. Weiss s For large or small y, uncertainties in the kinematic variables become large Range in y Q 2 ~ xys Range in s Range of kinematics Detecting only the electron y max / y min ~ 10 Also detecting all hadrons y max / y min ~ 100 – Requires hermetic detector (no holes) Accelerator considerations limit s min – Depends on s max (dynamic range) At fixed s, changing the ratio E e / E ion can for some reactions improve resolution, particle identification (PID), and acceptance C. Weiss valence quarks/gluons non-pert. sea quarks/gluons radiative gluons/sea [Weiss 09] s To cover the physics we need… 3 Tanja Horn, EIC Detector Overview, EIC Advisory Committee 2011 Vacuum fluct. pQCD radiation

4. 1. To a large extent driven by exclusive physics 2. But not only... Hermeticity (also for hadronic reconstruction methods in DIS) Particle identification (also SIDIS) Momentum resolution (kinematic fitting to ensure exclusivity) Forward detection of recoil baryons Muon detection ( J/Ψ ) Photon detection (DVCS) Very forward detection (spectator tagging, diffractive, coherent nuclear, etc.) Vertex resolution (charm) Hadronic calorimetry (jet reconstruction) Detector Requirements Tanja Horn, EIC Detector Overview, EIC Advisory Committee 2011 4

5. Where do particles go - general p or A e Many processes of interest in e-p: Token example: 1 H(e,e’ π + )n 5 Tanja Horn, EIC Detector Overview, EIC Advisory Committee 2011 In general, e-p and even more e-A colliders have a large fraction of their science related to the detection of what happens to the ion beams. The struck quark remnants can be guided to go to the central detector region with Q 2 cuts, but the spectator quark or struck nucleus remnants will go in the forward (ion) direction. [Ent 10+] Even more processes in e-A: 1) “DIS” (electron-quark scattering)e + p  e’ + X 2) “Semi-Inclusive DIS (SIDIS)”e + p  e’ + meson + X 3) “Deep Exclusive Scattering (DES)”e + p  e’ + photon/meson + baryon 4) Diffractive Scatteringe + p  e’ + p + X 5) Target Fragmentatione + p  e’ + many mesons + baryons 1) “DIS”e + A  e’ + X 2) “SIDIS”e + A  e’ + meson + X 3) “Coherent DES”e + A  e’ + photon/meson + nucleus 4) Diffractive Scatteringe + A  e’ + A + X 5) Target Fragmentatione + A  e’ + many mesons + baryons 6) Evaporation processese + A  e’ + A’ + neutrons

6. 6 diffractiveDIS Diffractive and Deep Inelastic Scattering Tanja Horn, EIC Detector Overview, EIC Advisory Committee 2011 10° 5° Momentum (GeV/c) High-momentum mesons at small angles 4 on 250 GeV 4 on 50 GeV Angle (deg) 40206080100120140160180 Angle (deg) 40206080100120140160180 [W. Foreman 09] 40206080100120140160180 40206080100120140160180 Angle (deg) 10 1 1 No cuts Small angle detection important

7. Tanja Horn, EIC Detector Overview, EIC Advisory Committee 20117 [Horn 08+] recoil baryons scattered electronsmesons 4 on 250 GeV 4 on 30 GeV PID challenging 0.2 ° - 0.45 ° 0.2 ° - 2.5 ° ep → e'π + n Exclusive light meson kinematics Q 2 >10 GeV 2 Momentum (GeV/c) t (GeV 2 ) Lab Scattering Angle (deg) very high momenta electrons in central barrel, but p different  t/t ~ t/E p Θ~√t/E p Lab Scattering Angle (deg)

8. 8 EM Calorimeter Hadron Calorimeter Muon Detector EM Calorimeter Solenoid yoke + Hadronic Calorimeter Solenoid yoke + Muon Detector HTCC RICH Cerenkov Tracking 5 m solenoid JLab layout has conical rather than cylindrical forward / backward trackers (with line-of-sight from IP) JLab detector does not have the forward RICH inside the solenoid magnet JLab detector allocates space for Cerenkov (LTCC) in central barrel for high-momentum PID JLab interaction region has a larger ion beam crossing angle 50-60 mrad vs 10 mrad Minor differences Tanja Horn, EIC Detector Overview, EIC Advisory Committee 2011 JLab and BNL central detector layouts similar JLab BNL DIRC Cerenkov EM -Calorimeter HTCC Hadronic Calorimeter Tracking RICH EM -Calorimeter 5 m solenoid e - Beamp/A Beam

9. Central Detector 9 Tanja Horn, Introduction to EIC/detector concept, Exclusive Reactions Workshop 2010 3-4 T solenoid with about 4 m diameter TOF for low momenta π/K separation p/K: DIRC up to 7 GeV e/π: C 4 F 8 O LTCC up to 3 GeV Solenoid Yoke, Hadron Calorimeter, Muons Particle Identification Low-mass vertex tracker GEM-based central tracker Conical endcap trackers Solenoid yoke + Hadronic Calorimeter Solenoid yoke + Muon Detector LTCC / RICH Tracking Tracking Tanja Horn, EIC Detector Overview, EIC Advisory Committee 2011 9 precise vertex reconstruction (< 10 μ m)  separate Beauty and Charmed Meson BNL Detector R&D projects JLAB Detector R&D projects low radiation length extremely critical  low lepton energies 10 on 50 (s=2000 GeV 2 ) Momentum (GeV/c) Lab Scattering angle (deg) BaBar DIRC “Super-DIRC” 4 on 30 (s=480 GeV 2 ) DIRC+gas Cerenkov or (dual radiator barrel RICH)

10. Detector Endcaps 10 Tanja Horn, Introduction to EIC/detector concept, Exclusive Reactions Workshop 2010 Bore angle: ~45° (line-of-sight from IP) High-Threshold Cerenkov (e/π) Time-of-Flight Detectors ̶ Hadrons, event reconstruction, trigger Electromagnetic Calorimeter (e/π) Bore angle: 30-40° (line-of-sight from IP) Ring-Imaging Cerenkov (RICH) Time-of-Flight Detectors (event recon., trigger) Electromagnetic Calorimeter ̶ P re-shower for γ/π° -> γγ (very small opening angle at high p) Hadronic Calorimeter (jets) Muon detector (J/Ψ production at low Q 2 ) Space constraints Electron side (left) Ion side (right) Electron side has a lot of space Ion side limited by distance to FFQ quads (7 m @ MEIC, eRHIC similar) EM Calorimeter Hadron Calorimeter Muon Detector EM Calorimeter TOF HTCC RICH Tracking Tanja Horn, EIC Detector Overview, EIC Advisory Committee 2011 10 BNL Detector R&D projects JLAB Detector R&D projects

11. Δp/p ~ σp / BR 2 175° R1R1 R2R2 Crossing angle A 2 Tm dipole covering 3-5° eliminates divergence at small angles Only solenoid field B (not R) matters at very forward rapidities A 3° beam crossing angle moves the region of poor resolution away from the ion beam center line. – 2D problem! Tracker (not magnet!) radius R is important at central rapidities – Conical trackers improve resolution at endcap corners by (R 2 /R 1 ) 2 ~ 4 (not shown) position resolution σ ~ 100 microns – CLAS DCs designed for 150 microns particle momentum = 5 GeV/c 4 T ideal solenoid field cylindrical tracker with 1.25 m radius (R 1 ) Goal: dp/p ~ 1% @ 10 GeV/c 11 Tanja Horn, EIC Detector Overview, EIC Advisory Committee 2011 Resolution dp/p in solenoid

12. Forward Detection – 2T-m dipole Tanja Horn, EIC Detector Overview, EIC Advisory Committee 2011 12 Forward / Backward Spectrometers: 2m 4m Dipoles needed to have good forward momentum resolution and acceptance

13. Δp/p ~ σp / BR 2 175° R1R1 R2R2 Crossing angle A 2 Tm dipole covering 3-5° eliminates divergence at small angles Only solenoid field B (not R) matters at very forward rapidities A 3° beam crossing angle moves the region of poor resolution away from the ion beam center line. – 2D problem! Tracker (not magnet!) radius R is important at central rapidities – Conical trackers improve resolution at endcap corners by (R 2 /R 1 ) 2 ~ 4 (not shown) position resolution σ ~ 100 microns – CLAS DCs designed for 150 microns particle momentum = 5 GeV/c 4 T ideal solenoid field cylindrical tracker with 1.25 m radius (R 1 ) Goal: dp/p ~ 1% @ 10 GeV/c 13 Tanja Horn, EIC Detector Overview, EIC Advisory Committee 2011 Resolution dp/p in solenoid [Horn, Ent 08+]

14. Nuclear Science: Map t between t min and 1 (2?) GeV  Must cover between 1 and 5 degrees  Should cover between 0.5 and 5 degrees  Like to cover between 0.2 and 7 degrees  = 5  = 1.3 E p = 12 GeVE p = 30 GeVE p = 60 GeV t ~ E p 2  2  Angle recoil baryons = t ½ /E p t resolution ~  ~ 1 mr 14 Tanja Horn, EIC Detector Overview, EIC Advisory Committee 2011 Challenge at small angles – recoil baryons [Horn 08+] t (GeV 2 ) Lab Scattering angle (deg) t (GeV 2 ) Lab Scattering angle (deg) t (GeV 2 ) Lab Scattering angle (deg)

15. IP ultra forward hadron detection dipole low-Q 2 electron detection large aperture electron quads small diameter electron quads ion quads small angle hadron detection dipole central detector with endcaps EM Calorimeter Hadron Calorimeter Muon Detector EM Calorimeter Solenoid yoke + Hadronic Calorimeter Solenoid yoke + Muon Detector HTCC RICH Cerenkov Tracking 5 m solenoid 3° beam (crab) crossing angle TOF (+ DIRC ?) Tanja Horn, EIC Detector Overview, EIC Advisory Committee 2011 MEIC interaction region and central detector layout Apertures for small-angle ion and electron detection not shown 15

16. solenoid electron FFQs 50 mrad 0 mrad ion dipole w/ detectors (approximately to scale) ions electrons IP ion FFQs 2+3 m 2 m (“full-acceptance” detector) Three-stage strategy using 50 mrad crossing angle Detect particles with angles below 0.5° using 20 Tm dipole beyond ion FFQs. Distance IP – ion FFQs = 7 m (Driven by push to 0.5 degrees detection before ion FFQs) detectors Central detector, more detection space in ion direction as particles have higher momenta. Detect particles with angles down to 0.5° (10 mrad) before ion FFQs. Need 2 Tm dipole (for 100 GeV proton beams) in addition to central solenoid. 16 Tanja Horn, EIC Detector Overview, EIC Advisory Committee 2011 Forward Ion Detection

17. 17 IP electrons ions 8 m drift space after low-Q 2 tagger dipole Chromaticity Compensation Block IR Spin Rotator Arc end Chromaticity Compensation Block Arc end Very forward ion tagging 20 Tm analyzing dipole Tanja Horn, EIC Detector Overview, EIC Advisory Committee 2011 MEIC Interaction Region – forward tagging [Bogacz 10]

18. Present thinking: ion beam has 50 mr horizontal crossing angle Renders good advantages for very-forward particle detection 20 Tm dipole @ ~20 m from IP (Reminder: MEIC/ELIC scheme uses 50 mr crab crossing) 18 Tanja Horn, EIC Detector Overview, EIC Advisory Committee 2011 Use Crab Crossing for Very-Forward Detection [Zhang09+] ions

19. From arc where electrons exit and magnets on straight section Synchrotron radiation Random hadronic background Dominated by interaction of beam ions with residual gas in beam pipe between arc and IP Comparison of MEIC (at s = 4,000) and HERA (at s = 100,000) −Distance from ion exit arc to detector: 50 m / 120 m = 0.4 −Average hadron multiplicity: (4000 / 100000) 1/4 = 0.4 −p-p cross section (fixed target): σ(90 GeV) / σ(920 GeV) = 0.7 −At the same ion current and vacuum, MEIC background should be about 10% of HERA o Can run higher ion currents (0.1 A at HERA) o Good vacuum is easier to maintain in a shorter section of the ring Backgrounds do not seem to be a major problem for the MEIC −Placing high-luminosity detectors closer to ion exit arc helps with both background types −Signal-to-background will be considerably better at the MEIC than HERA o MEIC luminosity is more than 100 times higher (depending on kinematics) Backgrounds and detector placement 19 Tanja Horn, EIC Detector Overview, EIC Advisory Committee 2011 [R. Ent 10]

20. Tanja Horn, EIC Detector Overview, EIC Advisory Committee 2011 2 468 1.902 m 1.719 m 1214 D=120 mm 5.475 m 16 IP Combined function: 1.6 m, 2.230 T, -109 T/m  =4 mrad 4.50 m  =10 mrad p c /2.5 1.9 cm (p o /2.5) ZDC  =10 mrad  =4 mrad 1.1m 1.045 m 1.95 m 1.057 m neutrons beam D=120 mm 10 20 eRHIC - Geometry high-lumi IR with β*=5 cm, l*=4.5 m and 10 mrad crossing angle Interaction Region configuration for eRHIC [Aschenauer 11]

21. Tanja Horn, EIC Detector Overview, EIC Advisory Committee 2011 The New PheniX Spectrometer 21 e- p/A 4x100 central arm unidentified North  arm only muons Forward upgrade identified hadrons 5 GeVx50GeV20 GeV x 250 GeV No dependence on hadron beam energy Q 2 >0.1GeV 2 4GeV  >5 o 10GeV  >2 o 20GeV  >1 o New PheniX has close to full coverage for scattered lepton Design completely driven by AA, dA and pp physics program [Aschenauer 11]

22. Tanja Horn, EIC Detector Overview, EIC Advisory Committee 2011 The new STAR Detector MRPC ToF Barrel BB C FPD FMSFMS EMC Barrel EMC End Cap DAQ10 00 COMPLETE R&D TPC computing HFT FGT MTD Roman Pots Phase 2 Trigger and DAQ Upgrades Ongoing The new Detector matches kinematics of eRHIC – Particle ID, sufficent p T resolution, etc. at mid- rapidity – Upgrades in forward direction: increase capability at lower momentum 22 [Aschenauer 11]

23. Summary Tanja Horn, EIC@JLab - taking nucleon structure beyond the valence region, INT09-43W 23 Tanja Horn, EIC Detectors, INT10-3 JLab and BNL detector concepts generally similar Emphasis on small-angle coverage ̶ Three stage approach for forward hadron detection Detector is well suited for a wide range of experiments Integration with accelerator important Goal: hermetic detector with high resolution over full acceptance 23 Tanja Horn, EIC Detector Overview, EIC Advisory Committee 2011

24. Backup material Tanja Horn, EIC@JLab - taking nucleon structure beyond the valence region, INT09-43W 24 Tanja Horn, EIC Detector Overview, EIC Advisory Committee 2011

25. 25 Tanja Horn, EIC Detector Overview, EIC Advisory Committee 2011 Detector/IR – Forward & Very Forward Ion Final Focusing Quads (FFQs) at 7 meter, allowing ion detection down to 0.5 o before the FFQs (BSC area only 0.2 o ) Use large-aperture (10 cm radius) FFQs to detect particles between 0.3 and 0.5 o (or so) in few meters after ion FFQ triplet  x-y @ 12 meters from IP = 2 mm 12  beam-stay-clear  2.5 cm 0.3 o (0.5 o ) after 12 meter is 6 (10) cm Large dipole bend @ 20 meter from IP (to correct the 50 mr ion horizontal crossing angle) allows for very-small angle detection (< 0.3 o )  x-y @ 20 meters from IP = 0.2 mm 10  beam-stay-clear  2 mm 2 mm at 20 meter is only 0.1 mr…  (bend) of 29.9 and 30 GeV spectators is 0.7 mr = 2.7 mm @ 4 m Situation for zero-angle neutron detection very similar as at RHIC!  enough space for Roman Pots & small-angle calorimeters [R. Ent 10]

26. EIC – Detector R&D Items EM Calorimeter Hadron Calorimeter Muon Detector EM Calorimeter Solenoid yoke + Hadronic Calorimeter Solenoid yoke + Muon Detector HTCC RICH Cerenkov Tracking 5 m solenoid DIRC-based PID for EIC Central Detector Collaboration: JLab, GSI, CUA, ODU Front end readout module for detector DAQ and trigger system as continuation of 12 GeV efforts Jlab FE group (C. Cuevas) Improve radiation hardness of Silicon PMTs as continuation of 12-GeV/Hall D work Jlab RD&I group (C. Zorn) Large GEM tracker Collaboration: BNL, Florida Inst. Of Tech., Iowa State, LBNL, MIT, Riken, Stony Brook, Uva, Yale RICH at high momenta Collaboration: BNL, Florida Inst. Of Tech., Iowa State, LBNL, MIT, Riken, Stony Brook, Uva, Yale Development of a new detector technology for fiber sampling calorimeters Collaboration: UCLA, Texas A&M, Penn State 26 Tanja Horn, EIC Detector Overview, EIC Advisory Committee 2011 Liquid scintillator calorimetry for EIC Ohio University (J. Frantz)

27. First Model of eRHIC Detector E.C. Aschen auer Workshop on eRHIC-ePHENIX-eSTAR, March 2010 27  DIRC: not shown because of cut; modeled following Babar  no hadronic calorimeter and  -ID jet  CALIC technology combines  ID with HCAL EM-Calorimeter PbGl High Threshold Cerenkov fast trigger on e’ e/h separation Dual-Radiator RICH as LHCb / HERMES Traditional Drift-Chambers better GEM-Tracker Central Tracker as BaBar Si-Vertex as Zeus Hadronic Calorimeter [Aschenauer 11]

28. JLab - Detector Component Modeling [Collaboration: JLab, GSI, CUA, ODU]

29. 0.44843 m Q5 D5 Q4 90.08703 m 60.0559 m 10 0.2582 m 9/11/2015 29 3 m 4.5  =4 mrad 10.26m 39.98 m  =10.3255 mrad 10 mrad 5.3 m 0.315726 m 30 20  =0.0036745 mrad 30 GeV e - 325 GeV p 125 GeV/u ions eRHIC - Geometry high-lumi IR with β*=5 cm, l*=4.5 m and 10 mrad crossing angle Interaction Region configuration for eRHIC [Aschenauer 11]

30. 10 on 60 Modest (up to ~6 GeV) electron energies in central & forward-ion direction. Electrons create showers  electron detectors are typically compact. Scattered Electron Kinematics 30 Tanja Horn, EIC Detector Overview, EIC Advisory Committee 2011 Low-Q 2 electrons in electron endcap High-Q 2 electrons in central barrel: 1-2 < p < 4 GeV Momentum (GeV/c) Electron Scattering Angle (deg) [Horn 08+] Larger energies (up to E e ) in the forward-electron direction: low-Q 2 events.

31. Cross section: Pythia  ep : 0.030 – 0.060 mb Luminosity: 10 34 cm -1 s -1 = 10 7 mb -1 s -1 E.C. Aschen auer Workshop on eRHIC-ePHENIX-eSTAR, March 2010 31 low multiplicity 4-6 √s = 40-65 GeV N ch (ep) ~ N ch (eA) < N ch (pA)  no occupancy problem Interaction rate: 300 -600 kHz Some thought about rates [Aschenauer 11]