News from eRHIC Matt Lamont, Thomas Ullrich , William Foreman, Anders Kirleis , Michael Savastio , Elke Aschenauer

1. News from eRHICMatt Lamont,Thomas Ullrich,William Foreman,Anders Kirleis, Michael Savastio,ElkeAschenauerand the CAD-eRHIC Team EIC-Convener Meeting, AUG. 2009

2. eRHIC group in Physics EIC-Convener Meeting, AUG. 2009 • eRHIC taskforce formed • weekly meetings on EVO Thursday@2pm • concentrate on simulating “golden physics channels” and to develop tools/software to be used by collaboration • detector – IR design together with CAD • In process of hiring 2 PostDocs • Have 3 students over the summer • Information available openly for everybody at • http://www.eic.bnl.gov/ • https://wiki.bnl.gov/eic/index.php/Main_Page • Summer Work • generate tools to simulate have rapgap & pythia root-trees • work to provide dvcs, pepsi and Hermes-transversity generators • simulated dis & diffractive events for several energy settings • design a detector in Geant fitting in IP-2 • (software based on STAR & ATLAS) • generate tools to MC Geant root-trees • and a lot of more

3. Momentum vs. Theta of Scat. Electron All done by William Foreman 4+250 GeV DIS 4+250 GeV Diffractive • What we do: • Edit codes so only information for certain particles are plotted, both in DIS and diffractive 60o - 180o Theta (degrees) • What we see: • Differences between DIS and diffractive events • Different angle & momentum distributions depending on electron + proton energies 140o - 180o 10+100 GeV DIS 10+100 GeV Diffractive Momentum (GeV/c) EIC-Convener Meeting, AUG. 2009

4. π+ Momentum vs. Angle • What we see: • Angles at which pions are projected for different energies in both DIS and diffractive events • In DIS events, pions tend to be sent at much smaller angles compared to diffractive events 4+250 GeV DIS 4+250 GeV Diffractive 0o - 180o Theta (degrees) 10+100 GeV DIS 10+100 GeV Diffractive 0o - 180o We use this information to design the detector! Momentum (GeV/c) EIC-Convener Meeting, AUG. 2009

5. ERL-based eRHIC Design 5 mm 5 mm 5 mm 5 mm 20 GeV e-beam 16 GeV e-beam Common vacuum chamber 12 GeV e-beam 8 GeV e-beam 2 x 200 m SRF linac 4 (5) GeV per pass 5 (4) passes eRHIC detector Gap 5 mm total 0.3 T for 30 GeV Polarized e-gun 10-20 GeV ex 325 GeV p 130 GeV/u Au possibility of 30 GeV @ low current operation Beam dump MeRHIC detector Coherent e-cooler PHENIX STAR 4 to 5 vertically separated recirculating passes EIC-Convener Meeting, AUG. 2009

6. Geometrical constraints: If it is possible use the existing interaction region at RHIC 2 o’clock and wider tunnel to place the superconducting linac inside it. Minimize civil construction cost and re-use for eRHIC already built and installed linac. Medium Energy eRHIC Concept EIC-Convener Meeting, AUG. 2009

7. IR-Design for MeRHIC I • no synchrotron shielding included EIC-Convener Meeting, AUG. 2009

8. Detection from hadron beam fragments EIC-Convener Meeting, AUG. 2009 • Tagging from Au fragments and p in ep • suppress incoherent scattering / ensure exclusivity • neutrons are detected in ZDC • protons use magnetic rigidity Au:p 2.5:1 • DX magnets disturbs p tagging

9. IR-Design for MeRHIC II • no synchrotron shielding included • allows p and heavy ion decay product tagging EIC-Convener Meeting, AUG. 2009

10. First ideas for a detector concept Solenoid (4T) Dipol 3Tm Dipol 3Tm FPD FED // // ZDC / TRD r: 5 ft / 1.5m ~15m EIC-Convener Meeting, AUG. 2009

11. The (M)eRHICDetetor All the work was done by Anders Kirleis with a lot of help by PavelNevski Still need to model EMCal in barrel and include the already modeled DIRC EIC-Convener Meeting, AUG. 2009

12. Solenoid Magnetic Field in Z Dimension Magnetic Field (KG) Radial Dimension (cm) Z Dimension (cm) EIC-Convener Meeting, AUG. 2009

13. Solenoid Magnetic Field in Z Dimension Radial Dimension (cm) Z Dimension (cm) EIC-Convener Meeting, AUG. 2009

14. Dipole Magnetic Field in Y Dimension Magnetic Field (KG) Radial Dimension (cm) Z Dimension (cm) EIC-Convener Meeting, AUG. 2009

15. Dipole Magnetic Field in Y Dimension Radial Dimension (cm) Z Dimension (cm) EIC-Convener Meeting, AUG. 2009

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30. HITS DATA FROM A MYLAR TRACKING DETECTOR EIC-Convener Meeting, AUG. 2009

31. The √s vs. luminosity landscape Diffraction exclusive DIS (PS & VM) electro-weak exclusive DIS (DVCS) semi-inclusive DIS inclusive DIS 20x100 20x250 10x100 4x100 EIC-Convener Meeting, AUG. 2009

32. Existing Experiment Luminosities EIC-Convener Meeting, AUG. 2009 • Hera : • H1 and Zeus: • 1031cm-2s-1 • 27GeV e+/e- 920GeV p √s = 320GeV • did measure: • inclusive & semi-inclusive DIS • exclusive reactions (DVCS) • diffractive physics • electro-weak • Hermes: • fixed target 27GeV e+/e- √s=7.2GeV • polarised: 5x1031cm-2s-1; unpol: 1032-33cm-2s-1; • did measure: • inclusive & semi-inclusive DIS • exclusive reactions (DVCS, pS, VM) • spin physics

33. Existing Experiment Luminosities EIC-Convener Meeting, AUG. 2009 • CERN • Compass • fixed target 160GeV m+/m- √s=17GeV • polarised: ~1031cm-2s-1; unpol: 1032-33cm-2s-1; • did measure: • inclusive & semi-inclusive DIS • exclusive reactions (VM) • spin physics • plan to measure: • exclusive reactions (DVCS, PS) • Drell Yan • SMC, NMC and EMC very similar, with different beam energies