1. 1  Calorimetry  W-Scintillator & W-Si  compact and high resolution  Crystal calorimeters PbW & BGO BNL, Indiana University, Penn State Univ., UCLA, USTC, TAMU  Pre-Shower  W-Si  LYSO pixel array with readout via X-Y WLS fibers readout via X-Y WLS fibers Univ. Tecnica Valparaiso “Cartesian PreShower”  PID via Cerenkov  DIRC and timing info Catholic Univ. of America, Old Dominion, South Carolina, JLab, GSI Catholic Univ. of America, Old Dominion, South Carolina, JLab, GSI  RICH based on GEM readout  e-PID: GEM based TRD  eSTAR BNL, Indiana Univ., USTC, VECC, ANL BNL, Indiana Univ., USTC, VECC, ANL  Tracking BNL, Florida Inst. Of Technology, Iowa State, LBNL, MIT, Stony Brook, Temple, Jlab, Virginia, Yale   -Vertex: central and forward based on MAPS  Central: TPC/HBD provides low mass, good momentum, dE/dx, eID good momentum, dE/dx, eID Fast Layer:  -Megas or PImMS Fast Layer:  -Megas or PImMS Forward: Planar GEM detectors

2. 2e’t (Q 2 ) e L*L*L*L* x+ξ x-ξ H, H, E, E (x,ξ,t) ~ ~  J  p p’ Inclusive Reactions in ep/eA:  Physics: Structure Fcts.: F 2, F L  Very good electron id  find scattered lepton  Momentum/energy and angular resolution of e’ critical  scattered lepton  kinematics Semi-inclusive Reactions in ep/eA:  Physics: TMDs, Helicity PDFs  flavor separation, dihadron-corr.,…  Kaon asymmetries, cross sections  Kaon asymmetries, cross sections  Excellent particle ID  ±,K ±,p ± separation over a wide range in   full  -coverage around  *  Excellent vertex resolution  Charm, Bottom identification Exclusive Reactions in ep/eA:  Physics: GPDs, proton/nucleus imaging, DVCS, excl. VM/PS prod.  Exclusivity  large rapidity coverage  rapidity gap events  ↘ reconstruction of all particles in event  high resolution in t  Roman pots

3.  Scattered lepton:  E e = 5 GeV -2 <  < 1 E e = 30 GeV -4.5 <  < -1  Produced Hadrons:  increasing √s hadrons are boosted from forward rapidities  to backward   -3<  <3 covers entire p t & z-region important for physics 3 Emerging Detector Concept:  high acceptance -5 <  < 5 central detector  good PID ( ,K,p and lepton) and vertex resolution (< 5  m)  tracking and calorimeter same coverage  good momentum resolution, lepton PID  low material density  minimal multiple scattering and brems-strahlung  Magnetic field extremely critical to get good tracking resolution in forward direction  Integration of detector in IR design  very forward electron and proton/neutron detection  Roman Pots, ZDC, low e-tagger

4. 4 To Roman Pots Upstream low Q 2 tagger ECAL W-Scintillator PID: -1<  <1: DIRC or proximity focusing Aerogel-RICH 1<|  |<3: RICH Lepton-ID: -3 <  < 3: e/p 1<|  |<3: in addition Hcal response &  suppression via tracking 1<|  |<3: in addition Hcal response &  suppression via tracking |  |>3: ECal+Hcal response &  suppression via tracking -5<  <5: Tracking (TPC+GEM+MAPS) DIRC/proximity RICH  

5. 5  10 mrad crossing angle and crab-crossing  High gradient (200 T/m) large aperture Nb 3 Sn focusing magnets  Arranged free-field electron pass through the hadron triplet magnets  Integration with the detector: efficient separation and registration of low angle collision products  Gentle bending of the electrons to avoid SR impact in the detector e p eRHIC - Geometry high-lumi IR with β*=5 cm, l*=4.5 m and 10 mrad crossing angle 20x250 20x250 Generated Quad aperture limited RP (at 20m) accepted

6. 6 proton/neutron tag method o Measurement of t o Free of p-diss background o Higher M X range o to have high acceptance for Roman Pots / ZDC challenging Roman Pots / ZDC challenging  IR design  IR design Diffractive peak Large Rapidiy Gap method o X system and e’ measured o Proton dissociation background o High acceptance MYMYMYMY Q2Q2Q2Q2W How can we select events: two methods Need for roman pot spectrometer ANDZDC Need for Hcal in the forward region

7. 7 leading protons are never in the main detector acceptance at EIC (stage 1 and 2) eRHIC detector acceptance e’ (Q 2 ) e L*L*L*L* x+ξ x-ξ H, H, E, E (x,ξ,t) ~ ~  p p’ t REQUIREMENTS  Acceptance at large-|t|  proper design of quadrupole magnets  proper design of quadrupole magnets  Acceptance for the whole solid angle  High momentum resolution  radiation hardness

8. 5x100 GeV 20x250 GeV 8 Accepted in“Roman Pot” at 20m Quadrupoles acceptance 10s from the beam-pipe high ‐ |t| acceptance mainly limited by magnet aperture high ‐ |t| acceptance mainly limited by magnet aperture low ‐ |t| acceptance limited by beam envelop (~10σ) low ‐ |t| acceptance limited by beam envelop (~10σ) |t| ‐ resolution limited by |t| ‐ resolution limited by – beam angular divergence ~100μrad for small |t| – uncertainties in vertex (x,y,z) and transport – ~<5-10% resolution in t (follow RP at STAR) Simulation based on eRHIC Generated Quad aperture limited RP (at 20m) accepted 20x250

9. 9 Results from GEMINI++ for 50 GeV Au +/-5mrad acceptance totally sufficient Results: With an aperture of ±3 mrad we are in good shape enough “detection” power for t > 0.025 GeV 2 enough “detection” power for t > 0.025 GeV 2 below t ~ 0.02 GeV 2 photon detection in very forward direction below t ~ 0.02 GeV 2 photon detection in very forward directionQuestion: For some physics needed rejection power for incoherent: ~10 4 For some physics needed rejection power for incoherent: ~10 4  Critical: ZDC efficiency