1. E.C. AschenauerEIC EW Meeting, W&M, VA, May 20101

2. eRHIC Scope e-e-e-e- e+e+e+e+ p Unpolarized and polarized leptons 4-20 (30) GeV Polarized light ions (He 3 ) 215 GeV/u Light ions (d,Si,Cu) Heavy ions (Au,U) 50-100 (130) GeV/u Polarized protons 50-250 (325) GeV Electron accelerator RHIC 70% e - beam polarization goal polarized positrons? Center mass energy range: √s=28-200 GeV; L~100-1000xHera longitudinal and transverse polarisation for p/He-3 possible e-e-e-e- Mission: Studying the Physics of Strong Color Fields E.C. Aschenauer EIC EW Meeting, W&M, VA, May 20102

3. The Relativistic Heavy-Ion Collider @ BNL E.C. Aschenauer 3 RHIC BRAHMS PHOBOS PHENIX STAR AGS TANDEMS v = 0.99995  c = 186,000 miles/sec ERL Test Facility 12 o’clock proposed RF BOOSTER LINAC EBIS EIC EW Meeting, W&M, VA, May 2010

4. The 1 st /2 nd incarnation of a staged eRHIC E.C. Aschenauer EIC EW Meeting, W&M, VA, May 2010 STAR PHENIX 3 pass 4 GeV ERL Polarizede-gunBeamdump MeRHICdetector 2 x 200 m SRF linac 4 (5) GeV per pass 5 (4) passes 4 to 5 vertically separated recirculating passes Gap 5 mm total 0.3 T for 30 GeV 5 mm 20 GeV e-beam 16 GeV e-beam 12 GeV e-beam 8 GeV e-beam Common vacuum chamber 10-20 GeV e x 325 GeV p 130 GeV/u Au possibility of 30 GeV @ low current operation STAR PHENIX Polarizede-gunBeamdump Coherente-cooler eRHICdetector  WHY IP-12?  have Experimental Hall @ IP-12 size of STAR fully staged detector from MeRHIC to eRHIC fully staged detector from MeRHIC to eRHIC vertical space much bigger (room for HCal) vertical space much bigger (room for HCal) need to buy magnets only once need to buy magnets only once can stage detector components, i.e. hadronic calorimeter can stage detector components, i.e. hadronic calorimeter no moving of components (IP2  IP12) no moving of components (IP2  IP12) systematics reduced  same detector for all energies systematics reduced  same detector for all energies MeRHIC eRHIC with CeC p (A)e e Energy, GeV 250 (100) 4 325 (125) 20 Number of bunches111166 Bunch intensity (u), 10 11 2.0 0.3 1 2.0 (3) 0.24 Bunch charge, nC325 4 Beam current, mA320 50 420 50 Normalized emittance, 1e-6 m, 95% for p / rms for e 15731.225 Polarization, %70807080 rms bunch length, cm 200.24.90.2 β *, cm50 25 Luminosity, x 10 33, cm -2 s -1 0.1 -> 1 with CeC 2.8 4

5. STAR ePHENIX 5 100m |--------| 6 pass 2.5 GeV ERL 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 The latest design of eRHIC The most cost effective design RHIC: 325 GeV p or 130 GeV/u Au eRHIC staging all-in tunnel

6. © V. Litvinenko LINAC SS and ARC Design E.C. Aschenauer EIC EW Meeting, W&M, VA, May 20106 1.27 m beam high 30 GeV e + ring 30 GeV ERL 6 passes HE ERL passes passes LE ERL passes passes 30 GeV 25 GeV 20 GeV 15 GeV 10 GeV 5 GeV 5 GeV 1.27 m beam high e + ring 200 m ERL Linac © V. Litvinenko

7. 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 © 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 E.C. Aschenauer EIC EW Meeting, W&M, VA, May 20107 m Spinrotator

8. 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 EW Meeting, W&M, VA, May 20108  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

9. (M)eRHIC Luminosities E.C. Aschenauer EIC EW Meeting, W&M, VA, May 2010 Old Design: for MeRHIC without CEC 4 x 250: 1x10 32 cm -2 s -1 for MeRHIC with CEC 4 x 250: 1x10 33 cm -2 s -1 for eRHIC with CEC: 20 x 325:2.8x10 33 cm -2 s -1 New Design: for eRHIC with CEC: 20 x 325 with b* of 5cm: 1.4x10 34 cm -2 s -1 as the the luminosity does not depend on the energy of electron beam you can write it as for eRHIC (new design): 1.4 10 34 * E p /325 cm -2 s -1 so you can easily scale it going to 20x100 for example so for eRHIC assuming 50% operations efficiency one week corresponds to 0.5 * 604800(s in a week) * (1.4x10 34 cm -2 s -1 ) = 4*10 39 cm -1 so 4000pb -1 an operations efficiency of 50% is low, but conservative at this moment. For EIC systematic errors will be the limiting factor For EIC systematic errors will be the limiting factor i.e., g 1, F L,  g,  q i.e., g 1, F L,  g,  q 9

10. Questions about QCD  Confinement of color, or why are there no free quarks and gluons at a long distance? A very hard question to answer  What is the quark-gluon structure inside a hadron? Probes to “see” and “locate” the quarks and gluons, without disturbing them or interfering with their dynamics?  How do quarks and gluons form color neutral hadrons? Probes to “monitor” the hadronization process?  How to understand the spin of a hadron? Hadrons are a composite particle of quarks and gluons Hadrons are a composite particle of quarks and gluons  What is the physics behind the QCD mass scale? E.C. Aschenauer EIC EW Meeting, W&M, VA, May 201010  It represents the difference between QED and QCD  Can’t “see” it directly, but, it is behind the answers to all these questions it is behind the answers to all these questions The key to the solution The Gluon Lets try to answer: Lets try to answer:  What is the role of gluons and gluon self-interactions in nucleons and nuclei?  What is the internal landscape of the nucleons?  What is the nature of the spin of the proton?  What is the three-dimensional spatial landscape of nucleons?  What governs the transition of quarks and gluons into pions and nucleons? Lets try to answer: Lets try to answer:  What is the role of gluons and gluon self-interactions in nucleons and nuclei?  What is the internal landscape of the nucleons?  What is the nature of the spin of the proton?  What is the three-dimensional spatial landscape of nucleons?  What governs the transition of quarks and gluons into pions and nucleons?

11. The √s vs. minimum luminosity landscape E.C. Aschenauer EIC EW Meeting, W&M, VA, May 2010 semi-inclusive DIS inclusive DIS Diffraction electro-weak 4x100 10x100 20x100 20x250 exclusive DIS (DVCS) exclusive DIS (PS & VM) 4x50 H1/ZEUS: ~10 31 cm -2 s -1 Hermes: 5x10 31 -10 33 W 2 -dependence of c.s. neglected 11

12. 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 EW Meeting, W&M, VA, May 201012

13. Momentum vs. theta 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 EW Meeting, W&M, VA, May 2010 As more symmetric beam energies as more the scattered lepton goes forward 13

14. E.C. Aschenauer EIC EW Meeting, W&M, VA, May 2010 4x50 4x100 4x250 p e : 0-1 GeV p e : 1-2 GeV p e : 2-3 GeV p e : 3-4 GeV 14 No dependence on hadron beam energy Q 2 >0.1GeV 2 4GeV  >5 o 4GeV  >5 o 10GeV  >2 o 20GeV  >1 o

15. Momentum vs. angle of pions Same CM energy (63.3 GeV) What do we see:  For DIS: distribution is more “smeared” as energy balance becomes more symmetric  For diffractive: majority of pions at easily accessible angles, either forward or backward depending on proton/electron energy E.C. Aschenauer EIC EW Meeting, W&M, VA, May 201015

16. t for exclusive VM vs p’ angle E.C. AschenauerEIC EW Meeting, W&M, VA, May 2010 4 x 50 4 x 100 4 x 250 very strong correlation between t and “recoiling” proton angle  Roman pots need to be very well integrated in the lattice well integrated in the lattice  resolution on t! t=(p 4 -p 2 ) 2 = 2[(m p in.m p out )-(E in E out - p z in p z out )] 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 ) 16

17. A detector integrated into IR E.C. Aschenauer EIC EW Meeting, W&M, VA, May 201017 ZDC FPD  Dipoles needed to have good forward momentum resolution  Solenoid no magnetic field @ r ~ 0  DIRC, RICH hadron identification  , K, p  high-threshold Cerenkov  fast trigger for scattered lepton  radiation length very critical  low lepton energies FED a lot of space for polarimetry and luminosity measurements

18. Can we detect DVCS-protons and Au break up p E.C. Aschenauer EIC EW Meeting, W&M, VA, May 201018  track the protons through solenoid, quads and dipole with hector proton track  p=10% proton track  p=20% proton track  p=40% Equivalent to fragmenting protons from Au in Au optics (197/79:1 ~2.5:1) DVCS protons are fine, need more optimization for break-up protons

19. eRHIC Detector in Geant-3 E.C. Aschenauer EIC EW Meeting, W&M, VA, May 2010  DIRC: not shown because of cut; modeled following Babar  no hadronic calorimeter in barrel yet  investigate ILC technology to combine  ID with HCAL Drift Chambers centraltracking ala BaBar Silicon Strip detector ala Zeus EM-CalorimeterLeadGlas High Threshold Cerenkov fast trigger on e’ e/h separation Dual-RadiatorRICH ala HERMES Drift Chambers ala HERMES FDC 19 Need to adopt Geant-3 model to new IR concept

20. MeRHIC Detector in Geant-3 E.C. Aschenauer EIC EW Meeting, W&M, VA, May 201020

21. More Detector Concepts in the same framework E.C. Aschenauer EIC EW Meeting, W&M, VA, May 2010 Detector optimized for diffractive physics by Allen Caldwell “eSTAR” 21

22. STAR @ RHIC 22 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 EW Meeting, W&M, VA, May 2010

23. Kinematics at 4+100 23 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 EW Meeting, W&M, VA, May 2010

24. 24 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

25. What will the current PheniX see EIC EW Meeting, W&M, VA, May 201025 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

26. 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 EW Meeting, W&M, VA, May 201026 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

27. Summary  A lot of change/progress since the last EIC Collaboration meeting  new eRHIC design more elegant and staging is very naturaly included  working on costing of the new version  test many detector options eSTAR, ePHENIX and a dedicated detector eSTAR & ePHENIX look promising with some restrictions  need to adjust the dedicated detector design fully to the new IR design  will integrate luminosity and e/p-polarisation measurements on the next step  Need input from the EW community what is required for detector, machine and IR design  Submitted first detector LDRD to BNL  high resolution vertex detector based on CMOS pixel E.C. Aschenauer EIC EW Meeting, W&M, VA, May 201027

28. Quads for β*=5 cm © B.Parker E.C. Aschenauer EIC EW Meeting, W&M, VA, May 201028

29. Luminosities in electron-hadron collisions ELIC eRHIC II eRHIC e+A facilities © 2010 Plot by A.Accardi except eRHIC luminosity by V. Litvinenko HERA II E.C. Aschenauer EIC EW Meeting, W&M, VA, May 201029

30. Questions about QCD (biased list)  Confinement of color, or why there is no free quarks and gluons at a long distance? A very hard question to answer  What is the quark-gluon structure inside a hadron? Probes to “see” and “locate” the quarks and gluons, without disturbing them or interfering with their dynamics?  How quarks and gluons form color neutral hadrons? Probes to “monitor” the hadronization process?  How to understand the spin of a hadron? A composite particle of quarks and gluons  What is the physics behind the QCD mass scale?  … E.C. Aschenauer EIC EW Meeting, W&M, VA, May 2010  It represents the difference between QED and QCD  Can’t “see” it directly, but, it is behind the answers to all these questions it is behind the answers to all these questions The key to the solution The Gluon 30

31. Energies Simulated for kinematics Beam Energies E e + E p [GeV] Center-of-mass Energy [GeV] Events Produced 4+5028.3 4+10040.0 10+5044.7 4+25063.3 10+10063.3One million 20+5063.3 20+10089.4 10+250100 20+250141 E.C. Aschenauer EIC EW Meeting, W&M, VA, May 201031

32. E.C. Aschenauer EIC EW Meeting, W&M, VA, May 2010 STAR PHENIX 2 x 200 m SRF linac 4 (5) GeV per pass 5 (4) passes Polarizede-gun Beamdump 4 to 5 vertically separated recirculating passes Coherente-cooler 5 mm 20 GeV e-beam 16 GeV e-beam 12 GeV e-beam 8 GeV e-beam Common vacuum chamber Gap 5 mm total 0.3 T for 30 GeV MeRHICdetector 10-20 GeV e x 325 GeV p 130 GeV/u Au possibility of 30 GeV @ low current operation The 1 st incarnation from a staged eRHIC 32

33. IR-Design for MeRHIC IP-2 E.C. Aschenauer EIC EW Meeting, W&M, VA, May 2010  synchrotron shielding omitted  allows p and heavy ion decay product tagging  IP-2: height beam-pipe floor ~6’ (with digging ~10’)  limits detector design  no HCal in central detector 33

34. eSTAR ePHENIX eRHIC staging all-in tunnel energy of electron beam is increasing from 5 GeV to 30 GeV by building-up the linac s from 5 GeV to 30 GeV by building-up the linac s 2 SRF linac 1 -> 5 GeV per pass 4 (6) passes Vertically separated recirculating passes. # of passes will be chosen to optimize eRHIC cost Coherente-cooler 5 mm 20 GeV e-beam 15 GeV e-beam 10 GeV e-beam 5 GeV e-beam Common vacuum chamber Gap 5 mm total 0.3 T for 30 GeV eRHIC detector injector RHIC: 325 GeV p or 130 GeV/u Au The most cost effective design © V. Litvinenko The latest design of eRHIC E.C. Aschenauer EIC EW Meeting, W&M, VA, May 201034