1. E.C. AschenauerEIC INT Program, Seattle 2010 - Week 11

2. The Physics we want to study  What is the role of gluons and gluon self-interactions in nucleons and nuclei?  Observables in eA / ep: diffractive events: rapidity gap events, elastic VM production, DVCS structure functions F 2 A, F L A, F 2c A, F Lc A, F 2 p, F L p,………  What is the internal landscape of the nucleons?  What is the nature of the spin of the proton?  Observables in ep  inclusive, semi-inclusive Asymmetries  electroweak Asymmetries (  -Z interference, W +/- )  What is the three-dimensional spatial landscape of nucleons?  Observables in ep/eA  semi-inclusive single spin asymmetries (TMDs)  cross sections, SSA of exclusive VM, PS and DVCS (GPDs)  What governs the transition of quarks and gluons into pions and nucleons?  Observables in ep / eA semi-inclusive c.s., R eA, azimuthal distributions, jets E.C. Aschenauer EIC INT Program, Seattle 2010 - Week 12

3. eRHIC Scope e-e-e-e- e+e+e+e+ p Unpolarized and polarized leptons 5-20 (30) GeV Polarized light ions He 3 215 GeV/u Light ions (d,Si,Cu) Heavy ions (Au,U) 50-130 GeV/u Polarized protons 50-325 GeV Electron accelerator to be build RHICexisting 70% e - beam polarization goal polarized positrons? Center mass energy range: √s=30-200 GeV; L~100-1000xHera longitudinal and transverse polarization for p/He 3 possible e-e-e-e- E.C. Aschenauer Spin 2010, Juelich3 Kinematic Coverage

4. Kinematics of scat. electron Proton Energy 50 GeV 100 GeV 250 GeV Electron Energy 4 GeV 10 GeV 20 GeV 4 GeV 10 GeV 20 GeV E.C. Aschenauer EIC INT Program, Seattle 2010 - Week 1 scattered lepton goes to smaller angles for same Q 2 as √s increases 4 For any hadron beam energy Q 2 >0.1GeV 2 4GeV  >5 o 4GeV  >5 o 10GeV  >2 o 20GeV  >1 o

5. Kinematics of semi-inclusive hadrons E.C. Aschenauer EIC INT Program, Seattle 2010 - Week 15 4x1004x2504x50 momentum (GeV) no cuts: cuts: Q2 > 0.1 GeV && y 0.1 GeV && y < 0.9 GeV hadrons go more and more forward with increasing asymmetry in beam energies

6. Kinematics of elastic diffraction E.C. Aschenauer EIC INT Program, Seattle 2010 - Week 16 4x250 4x100 4x50 no cuts: cuts: Q2 > 0.1 GeV && y 0.1 GeV && y < 0.9 GeV decay products of  & J/ ψ go more and more forward with increasing asymmetry in beam energies

7. Diffractive Physics: p’ kinematics E.C. Aschenauer EIC INT Program, Seattle 2010 - Week 17 4 x 100 t=(p 4 -p 2 ) 2 = 2[(m p in.m p out )-(E in E out - p z in p z out )] 4 x 50 4 x 250 ? Diffraction: p’ need “roman pots” to detect the protons and a ZDC for neutrons t=(p 3 –p 1 ) 2 = m ρ 2 -Q 2 - 2(E γ* E ρ -p x γ* p x ρ -p y γ* p y ρ -p z γ* p z ρ )

8. Additional Remarks  General Remarks  detector should have stable acceptance to enable efficient running at different energies (5 GeV x 50 GeV to 30 GeVx325 GeV) reduces systematic  F L  tracker, ECal and  -ID coverage must be the same to have good momentum and p t resolution  Charm detection  structure functions detecting lepton form decay in addition to scattered via displaced vertex should be enough  charm in fragmentation need to reconstruct D 0 meson completely to measure its z good PID  also required for semi-inclusive physics lepton has only very little correlation to z of D-meson E.C. Aschenauer EIC INT Program, Seattle 2010 - Week 18

9. Measure g A (x) impact parameter dependent E.C. Aschenauer 9 What are the real requirements:  Momentum resolution  t resolution and range  what breakup particles need to be detected to veto incoherent, what is the angular range, what suppression factor?  n  ZDC     ECAL in front of ZDC  p very difficult because of over focussing of quads EIC INT Program, Seattle 2010 - Week 1 A. Caldwell, H. Kowalski Phys.Rev.C81:025203,2010

10. How to measure coherent diffraction in e+A ?  Beam angular divergence limits smallest outgoing  min for p/A that can be measured  Can measure the nucleus if it is separated from the beam in Si (Roman Pot) “beamline” detectors  p Tmin ~ p z A tan -1 θ min For beam energies = 100 GeV/n and θ min = 0.1 mrad θ min = 0.1 mrad  Large momentum kicks, much larger than binding energy (~8 MeV) than binding energy (~8 MeV)  Therefore, for large A, coherently diffractive nucleus cannot be separated from beamline without breaking up E.C. Aschenauer EIC INT Program, Seattle 2010 - Week 110 species (A) p Tmin (GeV/c) d (2)0.02 Si (28)0.22 Cu (64)0.51 In (115)0.92 Au (197)1.58 U (238)1.90

11. How to measure coherent diffraction in e+A ? E.C. Aschenauer EIC INT Program, Seattle 2010 - Week 111  Rely on rapidity gap method  simulations look good  high eff. high purity possible with gap alone possible with gap alone ~1% contamination ~1% contamination ~80% efficiency ~80% efficiency  depends critical on detector hermeticity hermeticity  improve further by veto on breakup of nuclei (DIS) breakup of nuclei (DIS)  Very critical  mandatory to detect nuclear fragments from breakup fragments from breakupPurityEfficiencyrapidity

12. eSTAR ePHENIX 100m |--------| Coherente-cooler 22.5 GeV 17.5GeV 12.5 GeV 7.5 GeV Common vacuum chamber 27.5 GeV 2.5 GeV Beam-dump Polarized e-gun eRHIC detector 25 GeV 20 GeV 15 GeV 10 GeV Common vacuum chamber 30 GeV 5 GeV 0.1 GeV RHIC: 325 GeV p or 130 GeV/u Au eRHIC: staging all-in tunnel Gap 5 mm total 0.3 T for 30 GeV SRF linac Vertically separated recirculating passes. # of passes will be chosen to optimize eRHIC cost energy of electron beam is increasing from 5 GeV to 30 GeV by building-up the linac s From RHIC to eRHIC E.C. Aschenauer Spin 2010, Juelich12 eRHIC IR1 p /Ae Energy (max), GeV325/13020 Number of bunches16674 nsec Bunch intensity (u), 10 11 2.00.24 Bunch charge, nC324 Beam current, mA420 50 Normalized emittance, 1e-6 m, 95% for p / rms for e 1.225 Polarization, %7080 rms bunch length, cm4.90.2 β *, cm55 Luminosity, cm -2 s -1 1.46 x 10 34 Luminosity for 30 GeV e-beam operation will be at 20% level

13. Emerging Detector Concept E.C. Aschenauer EIC INT Program, Seattle 2010 - Week 113 Forward / Backward Spectrometers: 2m 4m  central detector acceptance: very high coverage -5 <  < 5  Tracker and ECal coverage the same  crossing angle: 10 mrad;  y = 2cm and  x = 2/4cm (electron/proton direction)  Dipoles needed to have good forward momentum resolution and acceptance  DIRC, RICH hadron identification  , K, p  low radiation length extremely critical  low lepton energies  precise vertex reconstruction (< 10  m)  separate Beauty and Charmed Meson

14. First Model of eRHIC Detector E.C. Aschenauer EIC INT Program, Seattle 2010 - Week 114  DIRC: not shown because of cut; modeled following Babar modeled following Babar  no hadronic calorimeter and  -ID jet  CALIC technology combines  ID with HCAL EM-CalorimeterPbGl High Threshold Cerenkov fast trigger on e’ e/h separation Dual-RadiatorRICH as LHCb / HERMES TraditionalDrift-Chambers better GEM-Tracker Central Tracker as BaBar Si-Vertex as Zeus HadronicCalorimeter

15. Technology choices and needed R&D E.C. Aschenauer EIC INT Program, Seattle 2010 - Week 115  Some thoughts about technologies  LHC trackers have all to much radiation length GEM trackers and ILC Si detectors would be much better important to keep radiation length in hadron direction low important to keep radiation length in hadron direction low ILC-TPC endplate ~30% X o Babar/Belle no forward detectors  Forward calorimeters small moliere radius  PbWO 4 especially important for hadron direction  DVCS Preshower:  0 separation  Si-WO  Central calorimeter needs to be compact with a pointing geometry sampling calorimeter with accordion structure  Needed R&D  low mass trackers  compact calorimetry for inside solenoid  ion polarimetry  currently at best 5% systematic uncertainty at RHIC Bjoerken sum rule measurement requires ~2%

16. IR-Design 0.44 m Q5 D5 Q4 90 m 10 mrad 0.329 m 3.67 mrad 60 m 10 20 30 0.188036 m 18.8 m 16.8 m 6.33 mrad 4 m Dipole © D.Trbojevic 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 Assume 50% operations efficency  4fb -1 / week E.C. Aschenauer Spin 2010, Juelich16 Spinrotator

17. A detector integrated into IR E.C. Aschenauer EIC INT Program, Seattle 2010 - Week 117 ZDC FPD  for ERL solution need not to measure electron polarization bunch by bunch  need still to integrate luminosity monitor  need still to integrate hadronic polarimeters, maybe at different IP FED space for e-polarimetry and luminosity measurements

18. Can we detect DVCS-protons and Au break up p E.C. Aschenauer EIC INT Program, Seattle 2010 - Week 118  track the protons through solenoid, quads and dipole with hector  beam angular spread 0.1mrad at IR  Quads +/- 5mrad acceptance  Proton-beam: p’ z > 0.9p z  100 GeV: p t max < 0.45 GeV  t max < 0.2 GeV 2  Detector: acceptance starts Θ > 10 / 20 mrad  t min > 1 / 4 GeV 2  need more work to find a way to cover intermediate range  solution could be to do the same as for the electrons swap the dipole and quads  lumi goes down dipole and quads  lumi goes down proton track  p=10% proton track  p=20% Equivalent to fragmenting protons from Au in Au optics (197/79:1 ~2.5:1) proton track  p=40%

19.  Quite some progress on integrating detector in machine design  Main features of detector design identified and implemented in design BUT BUT  need more feedback on requirements from physics groups  which hopefully comes with defining the physics program for an EIC @ the INT  BNL: look into the possibilities to use existing detectors eSTAR, ePHENIX  eSTAR & ePHENIX look promising, but have some restrictions compared to a dedicated detector E.C. Aschenauer EIC INT Program, Seattle 2010 - Week 119 and Summary

20. E.C. Aschenauer EIC INT Program, Seattle 2010 - Week 120 BACKUP

21. solenoid electron FFQs 100 mrad 0 mrad ion dipole w/ detectors (approximately to scale) ions electrons IP detectors ion FFQs 2+3 m 2 m Make use of a 100 mr crossing angle for ions! Central detector, more detection space in ion direction as particles have higher momenta Distance IP – electron FFQs = 3.5 m Distance IP – ion FFQs = 7.0 m 100 mr crossing angle 3.5 m distance IP – electron FFQs  Easy to squeeze baby-size electron FFQs in here Jlab: Detector/IR cartoon E.C. Aschenauer 21EIC INT Program, Seattle 2010 - Week 1 Slides Rolf Ent

22. 4 on 60 11 on 60 1 H(e,e’π + )n SIDIS  Need Particle ID for p > 4 GeV in central region  DIRC won’t work, add threshold Cherenkov or RICH Need Particle ID for well above 4 GeV in forward region (< 30 o ?)  determines bore of solenoid In general:Region of interest up to ~10 GeV/c mesons Momentum ~ space needed for detection { { Jlab: Where do particles go - mesons E.C. Aschenauer EIC INT Program, Seattle 2010 - Week 122 Slides Rolf Ent

23. EM Calorimeter (30-50 cm) EM Calorimeter (30-50 cm) – Crystals, small area TOF (5-10 cm) TOF (5-10 cm) RICH (60-100 cm) RICH (60-100 cm) – C 4 F 8 O + Aerogel EM Calorimeter Hadron Calorimeter Muon Detector EM Calorimeter Solenoid yoke + Hadronic Calorimeter Solenoid yoke + Muon Detector TOF HTCC RICH RICH Tracking 2m 3m 2m IP is shown shifted left by 0.5 meter here, can be shifted IP is shown shifted left by 0.5 meter here, can be shifted – Determined by desired bore angle and forward tracking resolution – Flexibility of shifting IP also helps accelerator design at lower energies (gap/path length difference induced by change in crossing angle) Or DIRC (10 cm) + LTCC (60-80 cm) Or DIRC (10 cm) + LTCC (60-80 cm) –C 4 F 8 O gas –π/K: 4 - 9 GeV/c (threshold) –e/π: up to 2.7 GeV/c (LTCC) –K/ p : up to 4 GeV/c (DIRC) Jlab: Overview of Central Detector Layout E.C. Aschenauer EIC INT Program, Seattle 2010 - Week 123 Slides Rolf Ent

24. solenoid electron FFQs 100 mrad 0 mrad ion dipole w/ detectors (approximately to scale) ions electrons IP detectors ion FFQs 2+3 m 2 m Make use of a 100 mr crossing angle for ions! Detect particles with angles down to 0.5 o Need up to 2 Tm dipole bend, but not too much! Jlab: Detector/IR cartoon E.C. Aschenauer EIC INT Program, Seattle 2010 - Week 124 Slides Rolf Ent

25. Downstream dipole on ion beam line ONLY has several advantages Downstream dipole on ion beam line ONLY has several advantages – No synchrotron radiation – Electron quads can be placed close to IP – Dipole field not determined by electron energy – Positive particles are bent away from the electron beam – Long recoil baryon flight path gives access to low -t – Dipole does not interfere with RICH and forward calorimeters Excellent acceptance (hermeticity) Excellent acceptance (hermeticity) solenoid electron FFQs 100 mrad 0 mrad ion dipole w/ detectors (approximately to scale) ions electrons IP detectors ion FFQs 2+3 m 2 m exclusive mesons 0.2 - 2.5° recoil baryons 4 on 30 GeV Q 2 > 10 GeV 2 Make use of a 100 mr crossing angle for ions! Slides Rolf Ent Jlab: Detector/IR cartoon E.C. Aschenauer EIC INT Program, Seattle 2010 - Week 125

26. Processes used to study the Physics E.C. Aschenauer EIC INT Program, Seattle 2010 - Week 126 exclusive /diffractive reactions ep/A  e’p’/A’VM semi-inclusivereactions ep/A  e’  X electro-weakreactions inclusivereactions ep/A  e’X Close to 4  acceptance Excellentelectronidentification PID: to identify Hadrons Backgroundsuppression Detectoutgoingscattered proton proton Detect very low Q 2 electron good jet identification excellentabsoluteand/orrelativeluminosity very precise polarizationmeasurement high demands on momentum and/or energy resolution good vertex resolution

27. Detector Requirements from Physics  Detector must be multi-purpose  Need the same detector for inclusive (ep -> e’X), semi-inclusive (ep -> e’hadron(s)X), exclusive (ep -> e’  p) reactions and eA interactions  Able to run for different energies (and ep/A kinematics) to reduce systematic errors reduce systematic errors  Ability to tag the struck nucleus in exclusive and diffractive eA reactions  Needs to have large acceptance  Cover both mid- and forward-rapidity  particle detection to very low scattering angle; around 1 o in e and p/A direction  particle identification is crucial  e, , K, p, n over wide momentum range and scattering angle  excellent secondary vertex resolution (charm)  small systematic uncertainty for e,p-beam polarization and luminosity measurement E.C. Aschenauer EIC INT Program, Seattle 2010 - Week 127

28. eRHIC – Geometry high-lumi IR 1.6 m 1 32 45 6 0.85 m 7 10 mrad 5.4 cm 8.4 cm 10.4 cm 1 m © D.Trbojevic E.C. Aschenauer EIC INT Program, Seattle 2010 - Week 128  Two designs of the IR exist for both low luminosity (~ 3x10 33 ) and high luminosity (~ 2x10 34 ) depends on distance IR to focusing quads  By using a crossing angle (and crab cavities), one can have energy- independent geometries for the IRs and no synchrotron radiation in the detectors  Big advantage in detecting particles at low angle  can go as low as 0.75 o at hadron side  |  | < 5.5 Beam-p: y ~ 6.2 m eRHIC IR1 p /Ae Energy (max), GeV325/13020 Number of bunches16674 nsec Bunch intensity (u), 10 11 2.00.24 Bunch charge, nC324 Beam current, mA420 50 Normalized emittance, 1e-6 m, 95% for p / rms for e 1.225 Polarization, %7080 rms bunch length, cm4.90.2 β *, cm55 Luminosity, cm -2 s -1 1.46 x 10 34 (including hour-glass effect h=0.851) Luminosity for 30 GeV e-beam operation will be at 20% level

29. STAR @ RHIC 29 Heavy Flavor Tracker (2013) Tracking: TPC Forward Gem Tracker (2011) Electromagnetic Calorimetry: BEMC+EEMC+FMS (-1 ≤  ≤ 4) Particle ID: TOF Full azimuthal particle identification over a broad range in pseudorapidity Upgrades: Muon Tracking Detector HLT E.C. Aschenauer EIC INT Program, Seattle 2010 - Week 1

30. Kinematics at 4+100 30 Scattered electron Scattered jet 4x100 open kinematics: scatters the electron and jet to mid-rapidity Forward region (FMS): Electron either Q 2 < 1 GeV, or very high x and Q 2 Jet either very soft or very hard Note: current thinking has hadron in the blue beam: optimized for high x and Q 2 E.C. Aschenauer EIC INT Program, Seattle 2010 - Week 1

31. 31 Current PHENIX Detector at RHIC MPC 3.1 < |  | < 3.9 2.5 o <  < 5.2 o 2.5 o <  < 5.2 o Muon Arms 1.2 < |  | < 2.4 South: 12 o <  < 37 o South: 12 o <  < 37 o North: 10 o <  < 37 o North: 10 o <  < 37 o Central Arms |  | < 0.35 60 o <  < 110 o 60 o <  < 110 o e- electrons will not make it to the south muon arm  to much material  would like to have hadrons in blue beam and leptons in yellow beam direction E.C. Aschenauer

32. What will the current PheniX see EIC INT Program, Seattle 2010 - Week 132 4x100 p e : 0-1 GeV p e : 1-2 GeV p e : 2-3 GeV p e : 3-4 GeV 4x100 4x100 Current PheniX detector not really useable for DIS DIS acceptance not matched to DIS kinematics BUT …. E.C. Aschenauer

33. HCAL EM CAL Preshower The new PheniX Spectrometer  Coverage in |  | =< 4 (2 o <  < 30 o ) 0.1 < Q 2 < 100 (5 o – 175 o )  need an open geometry detector  planes for next decadal plan replace current central detector with a new one covering |  | =< 1 replace South muon arm by a endcap spectrometer EIC INT Program, Seattle 2010 - Week 133 60cm 2T Solenoid EMCAL HCAL Silicon Tracker VTX + 1 layer Silicon Tracker FVTX 1.2 <  < 2.7 8 o <  < 37 o 8 o <  < 37 o North Muon Arm 68cm IP 80cm 145cm 5 o @ 2m 17.4 cm  y E.C. Aschenauer Summary: the new PheniX detector can make important measurements important measurements in ep/eA Lets integrate it fully into the design and the next decadal plan