1. Jin Huang (LANL) for the PHENIX collaboration

2.  PHENIX collaboration actively pursue forward upgrade  Wide spectrum of forward physics considered  A upgrade path that supports pp, pA, ep, eA collisions ◦ Assuming EIC start at 2025; ◦ On the path, hadron collisions benefit from upgrade starting ~2019 Workshop on Forward upgrades Jin Huang 2 q h ** e’e’ e

3.  Distribution of quarks and gluons and their spins in space and momentum inside the nucleon ◦ Nucleon helicity structure ◦ Parton transverse motion in the nucleon ◦ Spatial distribution of partons and parton orbital angular momentum  QCD in nuclei ◦ Nuclear modification of parton distributions ◦ Gluon saturation ◦ Propagation/Hadronization in nuclear matter  Outlined in EIC white paper, arXiv:1212.1701  LOI charged to both PHENIX and STAR Workshop on Forward upgrades Jin Huang 3 q h ** e’e’ e EIC coverage/ world data comparison: Helicity structure function SIDIS Sivers AsymmetriesDVCS

4.  DY SSA (A N ) gives access to, among others, quark Sivers effect (f 1T ⊥ ) in proton ◦ f 1T ⊥ expected to reverse in sign from SIDIS to DY measurement, an important test for gauge-link understanding of TMD ◦ Testing the size of TMD evolutions ◦ Probing orbital motion of partons  Require forward di-lepton detection Workshop on Forward upgrades Jin Huang 4 One-year running projection proton μ-μ- μ+μ+ lepton pion Semi-inclusive DIS (SIDIS) Drell-Yan Courtesy to M. Burkardt

5. Jet/photon left-right asymmetry  Probes Sivers effect: parton level correlation between spin and transverse momentum  Detector: require good jet reconstruction Left-right asymmetry of identified hadron inside jets  Collins fragmentation: transverse quark spin → k T of hadron  Probes: quark transversity and tensor charge  Detector: + PID inside the jet Workshop on Forward upgrades Jin Huang 5 Separating origin of A N with Jet measurements

6.  Forward observables allows probe low-x region in nuclei  Hadron transverse spin asymmetry ◦ Link between TMD and CGC framework, relates transverse single spin asymmetry to saturation scale ◦ Allowed by unique capability of RHIC to collide polarized proton with ions and protons  Di-Jet measurement ◦ Probe both flavors of distribution for gluon at low-x limits, G (1) & G (2) Workshop on Forward upgrades Jin Huang 6 Kang, Yuan PRD84 (2011) 034019

7. With detection capability beyond Bjorken plateau:  Correlation measurements → longitudinal expansion (3d-hydro)  Direct photons → the expansion of the medium  Extended (di-)jet coverage → jet energy loss in the medium  Suppression measurements → test linear factorization  Additional handle for critical point search Workshop on Forward upgrades Jin Huang 7

8.  PHENIX has been planning upgrade programs aimed at both central and forward region ◦ Central MIE sent to DOE by BNL Apr 2013  Productive series of workfests hosted to brainstorm/develop forward detector designs ◦ Recent workshops: May 2013 @ Santa Fe and July 2013 @ Japan/RIKEN  Current progress ◦ Converging on detector concept designs ◦ Performance quantified in first order ◦ Developing GEANT simulation models  ePHENIX LOI writing committee formed, planned collaboration release at end of August Workshop on Forward upgrades Jin Huang 8 e/sPHENIX forward workfest, Santa Fe, May 21-25

9.  Use jets as a tool to investigate the constituents and dynamics of the sQGP in the region of strongest coupling through its transport coefficients  Detector package: Solenoidal field/Central silicon tracking/EMCal+Preshower/HCal  Steady progress ◦ Started in 2009 with PHENIX decadal plans ◦ Initial MIE submitted to BNL June 2012 ◦ BNL administered review Oct 2012 ◦ MIE sent to DOE by BNL Apr 2013  Compatible with forward designs Workshop on Forward upgrades Jin Huang 9 arXiv:1207.6378, and updates

10. Workshop on Forward upgrades Jin Huang 10 1.684 m IP 4.50 m  =10 mrad 1.9 cm (p o /2.5) ZDC  =10 mrad  =4 mrad 1.06 m 1.0 m 1.95 m 0.845 m neutrons Ion beam 2 4 6 8 1212 1414 16 1010 0.1107 m 0.133 m Electron quadrupoles Combined function magnet Quad 3 Quad 2 3 11.0364m 5 mrad From D. Trbojevic e e p/A  Upgrade path that supports pp/pA/AA, then ep/eA physics ◦ Jets, lepton and photons over a large range in rapidity (1<η<4) ◦ Hadron PID in the forward region ◦ Additional backward+central electron measurement in EIC stage  Compatible with central arm upgrade  Fit in the default IR for s/ePHENIX ◦ IR limit in Z = 4.5m ◦ Height limit of beam-rail of 4.5 m ◦ No bending magnetic field on beam

11.  Cancelation of SuperB has made BaBar solenoid potentially available  Favor for forward tracking ◦ Longer field volume (L x~2) ◦ Higher current density at end of the magnet ◦ Quantified by comparison to the default and extended sPHENIX solenoid  At ALD’s request, drafting an official letter to express interest in acquiring the magnet Workshop on Forward upgrades Jin Huang 11 Tracking resolution based on field calculation Babar magnet VS longer MIE sPHENIX magnet BaBar solenoid in its transfer frame, May 17 2013 Longer Magnet Babar

12. Workshop on Forward upgrades Jin Huang 12 Aerogel & RICH GEM Station4 HCal GEM Station2 z (cm) R (cm) HCal η~1 η~4 η~-1 R (cm) GEM Station3 Silicon Station1 MuID pp 3 Hep pA AA Forward field shaper (later slides) Numerical field calculation from POISSION shown Crosschecked with Opera/FEM and used in analysis of later slides

13. Workshop on Forward upgrades Jin Huang 13 p/A e-e- e-e- Aerogel & RICH GEM Station4 HCal GEM Station2 z (cm) R (cm) HCal GEMs μ-TPC DIRC η~1 η~4 -1.2 R (cm) GEM Station3 GEMs Station1 η~-1

14. Design FamilyExample Piston Passive piston (C. L. da Silva) Super conducting piston (Y. Goto) Dipole Forward dipole (Y. Goto, A. Deshpande, et. al.) Redirect magnetic flux of solenoid (T. Hemmick) Use less-magnetic material for a azimuthal portion of central H-Cal (E. Kistenev) Toroid Air core toroid (E. Kistenev) Six fold toroid (J. Huang) Other axial symmetric Field shaper Large field solenoidal extension (C. L. da Silva) Pancake field pusher (T. Hemmick) Workshop on Forward upgrades Jin Huang 14 Beam line magnetic field shielding, based on superconducting pipe. Test device planned (Stony Brook Group) B

15. Workshop on Forward upgrades Jin Huang 15 B Track by C. L. da Silva

16.  Advantage : ◦ Significantly improved very forward field where Babar field is least effective ◦ Simple implementation ◦ Minimal interaction with Babar field and beam  Challenges that under study ◦ Background shower from piston ◦ Further improvement limited by total piston flux (may use silicon detector) Workshop on Forward upgrades Jin Huang 16 by C. L. da Silva Piston area

17.  Cherenkov detector for hadron ID ◦ p<~10 GeV/c: aerogel radiator ◦ p>~10 GeV/c: gas radiator ◦ Statistical separation under study, considering  Photon fluctuation and detection error  Tracking resolution  Field bending (next slides) ◦ Promising hadron PID capability demonstrated  EM Calorimeter ◦ Restacking of the current PHENIX calorimeter ◦ σ(E)/E ~ 8%/√E  Hadronic calorimeter ◦ New iron scintillator sample calorimeter ◦ Also serve as field return ◦ σ(E)/E ~ 90%/√E  Other PID options under study ◦ Stack of threshold Cherenkov detectors ◦ High precision TOF detectors Workshop on Forward upgrades Jin Huang 17 Purity of hadron sample using CF 4 RICH by T. Erdenejargal (U. Colorado) dp/p = 0.5% x p assumed Evaluated 10x250 EIC at η=3 Purity Proton not firing RICH −π−K−p−π−K−p Stat. limit

18. Workshop on Forward upgrades Jin Huang 18 Track  Field calculated numerically with field return  Field lines mostly parallel to tracks in the RICH volume  Field distortion of RICH ring only contribute to a minor uncertainty RICH GEM Station3 HCal A RICH Ring: Photon distribution due to tracking bending only R Dispersion ΔR <2 mrad Dispersion ΔR <2 mrad R < 52 mrad for C 4 F 10

19.  Initial study of pointing resolution ◦ 1<η<3: 0.01-0.03 (rad or η unit) ◦ 3<η<4: ~0.05 (rad or η unit) Workshop on Forward upgrades Jin Huang 19 by Mike M. Azimuthal difference VS E True Azimuthal Resolution VS E True E reco VS E true : 1<η<22<η<33<η<4

20.  2D Field calculation using three tools and cross check ◦ Opera/FEM/POISSION  Simulation implementation in Geant4 Workshop on Forward upgrades Jin Huang 20 PYTHIA 5x50 GeV e-p event in GEANT4 by C. Pinkenburg 30 GeV electron track and shower in hadron endcap, by C. L. da Silva

21.  PHENIX collaboration actively pursue forward upgrade  Wide spectrum of forward physics and collision species considered ◦ For pp/pA/AA collisions : multi-dimentional hadron structure, cold nuclear matter, critical point search and 3d-hydro ◦ For EIC stage-I, ep/eA collisions: Nucleon helicity and multi-dimentional structure, Nuclear modification, Gluon saturation, Propagation/Hadronization in nuclear matter  Upgrade path for both hadron and EIC collisions ◦ Fit into geometry constraint, no field on beam line ◦ Converging on detector concept and upgrade path ◦ Providing a large rapidity coverage and comprehensive PID capability ◦ Quantifying detector performance Workshop on Forward upgrades Jin Huang 21