PheniX, STAr AND AN EIC E.C. Aschenauer EIC INT Program, Seattle 2010, Week 10

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 F2A, FLA, F2cA, FLcA, F2p, FLp,……… 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 (g-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., ReA, azimuthal distributions, jets E.C. Aschenauer EIC INT Program, Seattle 2010, Week 10

Kinematic Plane E.C. Aschenauer EIC INT Program, Seattle 2010, Week 10 Need to study hadronic method to increase y acceptance E.C. Aschenauer EIC INT Program, Seattle 2010, Week 10

Lepton Kinematics Follow Hera Convention: Hadron beam positive z (=> q = 0o)  Lepton beam negative z => q = 180o) E.C. Aschenauer EIC INT Program, Seattle 2010, Week 10

Hadron Kinematics E.C. Aschenauer EIC INT Program, Seattle 2010, Week 10

Kinematics of elastic diffraction no cuts: 4x100 4x50 4x250 cuts: Q2 > 0.1 GeV && y < 0.9 GeV decay products of r & J/ψ go more and more forward with increasing asymmetry in beam energies E.C. Aschenauer EIC INT Program, Seattle 2010, Week 10

Diffractive Physics: p’ kinematics t=(p4-p2)2 = 2[(mpin.mpout)-(EinEout - pzinpzout)] 4 x 50 ? Diffraction: recoil protons and break-up particles from Au need dedicated forward detectors 4 x 100 4 x 250 E.C. Aschenauer EIC INT Program, Seattle 2010, Week 10

IP configuration for eRHIC Nice design for protons from exclusive reactions and nuclear breakup particles pt > 1.5GeV  main detector 0.1 MeV < pt < 1GeV after dipole 4.5 cm pc/2.5 neutrons 90 mm q=44 mrad 6 mrad 3.5 m pc/2.5 11.2 cm 2.5 m 15.7 cm 5.75 m q=18 mrad 4.5 m ZDC 6.3 cm q=10 mrad IP 2 4 6 8 10 12 14 16 Dipole: 2.5 m, 6Tm q=18 mrad Estimated b*≈ 8 cm E.C. Aschenauer EIC INT Program, Seattle 2010, Week 10

IR Design eRHIC - Geometry high-lumi IR with β*= 8cm, l*=4.5 m and 10 mrad crossing angle Dipole to separate p/A beam from “recoil”/breakup particles q=27.194 mrad Q4 Q5 D5 325 GeV p Or 125 GeV/u ions 4 m 11.9 m q=18 mrad 5.75 m 0.44843 m 0.333 m 0.39065 m 10 mrad 30 GeV e- 5.75 cm 4.5 10 20 30 17.65 m 60.0559 m 90.08703 m © D.Trbojevic E.C. Aschenauer EIC INT Program, Seattle 2010, Week 10

Current PHENIX Detector at RHIC MPC 3.1 < | h | < 3.9 2.5o < Q < 5.2o Muon Arms 1.2 < | h | < 2.4 South: 12o < Q < 37o North: 10o < Q < 37o Central Arms | h | < 0.35 60o < Q < 110o electrons will not make it to the south muon arm  to much material p/A e- E.C. Aschenauer EIC INT Program, Seattle 2010, Week 10

What will the current PheniX see pe: 0-1 GeV pe: 1-2 GeV pe: 2-3 GeV pe: 3-4 GeV 4x100 Current PheniX detector not really useable for DIS acceptance not matched to DIS kinematics 4x100 4x100 E.C. Aschenauer EIC INT Program, Seattle 2010, Week 10

The New PheniX Spectrometer Design completely driven by AA, dA and pp physics program p/A e- E.C. Aschenauer EIC INT Program, Seattle 2010, Week 10

What can we detect pe: 0-1 GeV pe: 1-2 GeV pe: 2-3 GeV pe: 3-4 GeV No dependence on hadron beam energy Q2>0.1GeV2 4GeV  >5o 10GeV  >2o 20GeV  >1o New PheniX has close to full coverage for scattered lepton 4x50 Forward upgrade identified hadrons 5 GeVx50GeV 20 GeV x 250 GeV 4x100 central arm unidentified North m arm only muons E.C. Aschenauer EIC INT Program, Seattle 2010, Week 10

Electromagnetic Calorimetry: The STAR Detector Tracking: TPC Particle ID: TOF Electromagnetic Calorimetry: BEMC+EEMC+FMS (-1 ≤  ≤ 4) Upgrades: Muon Telescope Detector Roman Pots Phase 2 Forward Upgrade Heavy Flavor Tracker (2013) Forward Gem Tracker (2011) Full azimuthal particle identification over a broad range in pseudorapidity E.C. Aschenauer EIC INT Program, Seattle 2010, Week 10

STAR Experiment as of 2014 MTD EMC Barrel MRPC ToF Barrel EMC End Cap FMS BBC FPD TPC Roman Pots Phase 2 computing DAQ1000 COMPLETE Trigger and DAQ Upgrades HFT FGT Ongoing R&D E.C. Aschenauer EIC INT Program, Seattle 2010, Week 10

STAR Forward Upgrade proton nucleus Positive η: Drell Yan High precision tracking and background rejection using calorimetry Optimized for p+A and p+p High momentum scale Negative η: eRHIC Optimized for low energy electrons (~1 GeV) Triggering, tracking, identification R&D necessary for optimal technology choice Switch colors of the beams nucleus electron To fully investigate cold QCD matter, STAR will move forward E.C. Aschenauer EIC INT Program, Seattle 2010, Week 10

Energy loss in cold QCD matter RAπ Hermes, Nucl. Phys.B 780, 1 (2007) Lc ∝ ν: Lc up to few 100 fm Complementary probe of mechanism of energy loss HERMES: mixture of hadronic absorption and partonic loss Hadrons can form partially inside the medium eRHIC: light quarks form far outside medium Heavy quarks: unexplored to date. Low β: short formation time E.C. Aschenauer EIC INT Program, Seattle 2010, Week 10

STAR and eRHIC Phase I Current detector matches quite well to kinematics of eRHIC Particle ID, sufficent pT resolution, etc. at mid-rapidity Upgrades in forward direction: increase capability at lower momentum Developing plan for effective and compelling use of e+A E.C. Aschenauer EIC INT Program, Seattle 2010, Week 10

Longer term: STAR and eRHIC Forward region critical for higher energy options Major upgrades in forward direction would be needed E.C. Aschenauer EIC INT Program, Seattle 2010, Week 10

Summary Both, the new PheniX and STAR have reasonable capabilities for ep/eA collisions inclusive measurements some initial semi-inclusive measurements as well as for heavy quarks BUT no replacement for a dedicated detector using STAR and/or PHENIX might help to release some of the requirements on the dedicated detector need still to resolve all the details how to bring the lepton beam with 10mrad in the detectors for collisions and the non-colliding beams around. STAR seems easier than PHENIX E.C. Aschenauer EIC INT Program, Seattle 2010, Week 10