MEIC Central Detector Zhiwen Zhao for JLab MEIC Study Group MEIC Collaboration Meeting 2015/10/07
MEIC Design Goals Energy Full coverage of s from 15 to 65 GeV Electrons 3-10 GeV, protons 20-100 GeV, ions 12-40 GeV/u Ion species Polarized light ions: p, d, 3 He, and possibly Li Un-polarized light to heavy ions up to A above 200 (Au, Pb) Space for at least 2 detectors Full acceptance is critical for the primary detector High luminosity for the second detector Luminosity 10 33 to 10 34 cm -2 s -1 per IP in a broad CM energy range Polarization At IP: longitudinal for both beams, transverse for ions only All polarizations >70% Upgrade to higher energies and luminosity possible 20 GeV electron, 250 GeV proton, and 100 GeV/u ion Design goals consistent with the White Paper requirements 2
EIC Physics Highlights 3D structure of nucleons How do gluons and quarks bind into 3D hadrons? Role of orbital motion and gluon dynamics in the proton spin Why do quarks contribute only ~30%? Gluons in nucleon and nuclei (light and heavy) Does the gluon density saturate at small x? Stage I JLab 12 GeV Stage I+II A stage I EIC (Jlab MEIC) covers the x and Q 2 range between JLab 12 GeV and HERA (or a future LHeC) 3
Interaction Region 50mrad Crossing Angle ions p (top view) IP 70 m e low-q 2 electron detection and Compton polarimeter central detector with endcaps far forward hadron detection Fully-integrated detector and interaction region satisfying Detector requirements: full acceptance and high resolution Beam dynamics requirements: consistent with non-linear dynamics requirements Geometric constraints: matched collider ring footprints 4
Semi-Inclusive DIS (SIDIS) (one physics example) 3-D Tomogra phy Nucleon Spin Models Precision mapping of transverse momentum dependent parton distributions (TMD) QCD Dynamics TMD Quark OAM / Spin Lattice QCD QCD Factorizat ion Highly polarized electron collide with highly polarized nuclei (proton, deuteron, 3 He,etc) Detect scattered electron and pion at full angle and full momentum range 5
ECAL TOF (modular) TOF 3 m Inner ECAL ECAL Coil wall Coil wall MEIC IP1 Central Detector Dual Solenoid Magnet, inner size similar to CLEO/BaBar magnet ele endcap barrel ion endcap p RICH (modular) HBD forward tracker Dual Solenoid in common cryostat 4 m long inner coil Central Field 3 Tesla DIRC IP ECAL TOF forward tracker Dual RICH Aerogel +CF 4 e Si-pixel vertex + disks central tracker (top view) HCAL+ muons 3 m 5 m 6
Tracking (Gas Electron Multiplier) 7
Tracking (Gas Electron Multiplier) Ionization GEM foil: 50 mm Kapton + few mm copper on both sides with 70 mm holes, 140 mm pitch Multiplication (x20) Multiplication (x20) Multiplication (x20) Readout Find particle tracks and measure momentum Work in high rate environment 8
Particle Identification Detector (Hadron Blind Detector) 9
Particle Identification Detector (Hadron Blind Detector) Reverse Bias HV g photo electron e - primary ionization Readout Pads Compact e/p PID detector Blind to hadron < 4GeV with CF 4 gas at PHENIX Tom Hemmick @ StonyBrook 10
Particle Identification Detector (Modular RICH) 11
Particle Identification Detector (Modular RICH) Concept Simulation in GEMC Compact p/k PID detector at ele endcap Flexible arrangement, can be projective to IP at ele endcap Final performance : Efficiency and mis-id VS momentum EIC R&D PID (RICH) 12
Particle Identification Detector (Dual Radiator RICH) 13
Particle Identification Detector (Dual Radiator RICH) p/k PID detector at ion endcap Aerogel with Fresnel lens ~75 cm focal length: image at focal point of mirror (also filter UV) CF 4 gas (visible + UV) 2 nd mirror to place photo sensors in weaker field? EIC R&D PID (RICH) 14
Particle Identification Detector (DIRC) 15
Particle Identification Detector (DIRC) Narrow radiator bars grouped to common prism/photosensor array Close-up view of focal image with spherical 3-layer lens with no air gap Detection of internally reflected Cherenkov light (DIRC) Compact PID detector at barrel 16
Particle Identification Detector (Time of Flight) 17
TOF (ns) Particle Identification Detector (Time of Flight) Preliminary Δt = t 2 t 1 = 25 ps σ t = Δt/ 2 = 18 ps Compact PID detector C. Williams et al 100 10 1 Ion Endcap (z=3.5 m) K-pi p-k p-pi Flexible arrangement, can be modular, can be at both endcaps and barrel EIC R&D PID (TOF) 0.1 0.01 0 1 2 3 4 5 6 Momentum (GeV/c) 18
Particle Identification Detector (EMCal) 19
Particle Identification Detector (EMCal) Panda Crystal endcap IHEP, COMPASS Shashlik, 2010 3D-printed scintillator at W&M Shashlik type at large angle with balanced performance and cost Crystal type at small angle compensate for tracking resolution Pb/SciFi type at barrel EIC R&D Calorimeter 20
SIDIS Kinematics Maximum hadron momentum vs hadron angle in contours of constant Q 2 or x Bj Hadron momentum scales with z Projected p/k PID 2 decades exploration in x B and Q 2 Barrel Charles Hyde @ ODU 21
High Luminosity Central Detector MEIC IP1 (full-acceptance central detector) Focus on exclusive processes and semi-inclusive DIS Several solenoid options available (approximately to scale) (side view of top half) ephenix detector MEIC IP2 (high luminosity central detector) Focus on jetphysics Possible to move ephenix to MEIC IP2? 22
Summary MEIC has fully-integrated detector and interaction region design IP1 central detector has full acceptance and high resolution IP2 will feature high luminosity central detector Detector technology has strong support from EIC R&D effort 23
Backup 24
Unified View of Nucleon Structure W pu (x,k T,r ) Wigner distributions 6D Dist. d 3 r d 2 k T dr z TMD PDFs f 1u (x,k T ), ( T.. h 1u (x,k GPDs/IPDs 3D imaging d 2 k T d 2 r T dx & Fourier Transformation PDFs ( x ) f 1u (x),.. h 1u 1D Form Factors G E (Q 2 ), ( 2 G M (Q
Nucleon Polarization Leading-Twist TMD PDFs Quark polarization Unpolarized (U) Longitudinally Polarized (L) Transversely Polarized (T) U f 1 = h 1 = Boer-Mulders L g 1 = Helicity h 1L = Worm Gear T f 1T = Sivers g 1T = Worm Gear h 1 = Collins/Transversity h 1T = Pretzelosity Nucleon Spin Quark Spin