1. 1 PheniX-Hardware Workshops Dec. 2010 E.C. Aschenauer

2. A symbiosis physics program with pp/dA and ep/eA  What is needed:  The forward upgrade and PID in the forward and central detector  What do we want to study Imaging QCD matter In momentum space In impact parameter space transverse momentum generalized parton distributions dependent distributions  exclusive reaction like DVCS E.C. Aschenauer PheniX-Hardware Workshops Dec. 2010 2 Polarized p d-quark u-quark

3. A symbiosis physics program with pp/dA and ep/eA  What do we want to study (cont.)  The spin structure of the nucleon  partons in the nuclear medium  Saturation  nPDFs  Fragmentation in nuclear medium E.C. Aschenauer PheniX-Hardware Workshops Dec. 2010 3 UNIVERSALITY

4. The New PheniX Spectrometer E.C. Aschenauer PheniX-Hardware Workshops Dec. 2010 4 Design completely driven by AA, dA and pp physics program e- p/A

5. Transversity and Sivers, what do we know PheniX-Hardware Workshops Dec. 2010 Anselmino et al. arXiv:0809.2677 x 5 Q 2 =2.4 GeV 2 Fit to SIDIS and e+e- Lattice: P. Haegler et al. lowest moment of distribution of unpol. q in transverse pol. proton ANL ZGS  s=4.9 GeV BNL AGS  s=6.6 GeV FNAL  s=19.4 GeV Big single spin asymmetries in p  p !! Naive pQCD (in a collinear picture) predicts A N ~  s m q /sqrt(s) ~ 0 What is the underlying process? Do they survive at high √s? Relation to SIDIS?  HP13 E.C. Aschenauer

6. Proposed mechanisms - Sivers - Collins - twist-3 effect (collinear) -... need other processes to test theory and disentangle underlying process Transverse Polarization Effects PheniX-Hardware Workshops Dec. 2010 6 Large A N observed in forward hadron production PRL 97, 152302 E.C. Aschenauer Left -Right

7. The way to HP13 E.C. Aschenauer PheniX-Hardware Workshops Dec. 2010 7 DIS: attractive FSI Drell-Yan: repulsive ISI QCD:QCD: Sivers DIS = - Sivers DY Q  QCD PTPT << PTPT Collinear/ twist-3 Transverse momentum dependent Both models expect sign change First ideas by theorists to separate underlying processes: A N for  -jet  sivers A N for   -jet  Collins Universality breaking Roger, Mulders hep-ph:1001.2977

8. PheniX-Hardware Workshops Dec. 2010 8  All charged particle pairs between J/  and   Hadron suppression 10 3 -10 4 needed at 500 GeV  Drell Yan signal reduced in 200 GeV forward Can we do DY 500 GeV 200 GeV E.C. Aschenauer

9.  Drell Yan signal  3 – 10 GeV/c 2  Energy cut  E 1,2 > 2 GeV  Forward rapidities  Effectively no background left  Statistically limited  Drell Yan for m inv < 3 GeV/c 2 not physical (PYTHIA settings) 2G PYTHIA events for hard QCD and diffractive processes 9 DY @ 500 GeV after cuts E.C. Aschenauer PheniX-Hardware Workshops Dec. 2010

10. Increase p-energy to 325 GeV and get polarized He 3 E.C. Aschenauer PheniX-Hardware Workshops Dec. 2010 10  Under isospin symmetry, U and D correlation function interchange  proton: u   + while T u,F proton > 0  A N > 0 for  +  neutron: u   + while T u,F neutron =T d,F proton < 0  A N < 0 for  + Big effect going from p to He-3  difference between  u and  d Twist-3 A N for identified Hadrons

11. pp @ 500 GeVHe3-p @ 432 GeV A L W : pp vs He3-p collisions 11 E.C. Aschenauer PheniX-Hardware Workshops Dec. 2010

12. What else can DY @ RHIC teach us PheniX-Hardware Workshops Dec. 2010 12 DIS DY RHIC Collisions recent review by Accardi et al, arXiv:0907.3534 dAu / pAu: no hadron formation  p t broadening only due to gluon radiation  determine Q s B. Z. Kopeliovich et al., Phys. Rev. C81 (2010) 035204 eAu: hadron formation in-/outside nucl. medium gluon radiation  p t broadening due to both effects  EIC:  wide  coverage   chose effect Parton Propagation in Nuclear Medium: E.C. Aschenauer Situation for DY in dAu should be very similar to pp in the d-beam side  low x

13. Various Measurements in dAu E.C. Aschenauer PheniX-Hardware Workshops Dec. 2010 13 nPDFs: Golden Channel  -Jet: deuteron Au Intrinsic Charm: high x f J/  :

14. PheniX-Hardware Workshops Dec. 2010 Saturation @ eRHIC teach us 14 Saturation:  dAu: Strong hints from RHIC at x ~ 10 -3  ep: Weak hints at Hera up to x=6.32 ⋅ 10 -5, Q 2 = 1-5 GeV 2 Nuclear Enhancement: Hera EIC Coverage:  Need lever arm in Q 2 at fixed x to constrain models  Need Q > Q s to study onset of saturation  eA: √s = 50 GeV is marginal, around √s = 100 GeV desirable  low mass DY  access to quark saturation?  universality of saturation E.C. Aschenauer

15. Saturation: Golden Channels in eA E.C. Aschenauer PheniX-Hardware Workshops Dec. 2010 15 Exclusive diffractive VM production:  eA  e’A’V  d  A /dt  F g (b) Experimental Aspects:  Photo-production cross section large & |t|~p t V2  J/  easy detection at  <2 well separated from background  Crucial: detecting breakup of nuclei  Need to measure e’ for Q 2 >10 -3 GeV 2

16. Saturation: Golden Channels in eA E.C. Aschenauer PheniX-Hardware Workshops Dec. 2010 16 W. Horowitz (work in progress): High energies: KLN/CGC like  (r) Is what matters not Wood-Saxon Th. Ullrich & T. Toll Dipole Model:

17. Inclusive Structure Functions E.C. Aschenauer 17 small x large x Observation of large scaling violations BNL Science Council, July 2010 Strong increase of sea quarks towards low x Density increases with Q 2 more partons by magnified view quark density Dynamic creation of partons at low x gluon density valence quarks x=1 x=10 -5 Gluon density dominates

18. F 2 : for Nuclei 18 E.C. Aschenauer BNL Science Council, July 2010 Assumptions:  10GeV x 100GeV/n  √s=63GeV  Ldt = 4/A fb -1  equiv to 3.8 10 33 cm -2 s -1  T=2weeks; DC:50%  Detector: 100% efficient  Q 2 up to kin. limit sx  Statistical errors only  Note: L~1/A antishadowing “sweet”spot R=1 shadowing LHC  =0 RHIC =3

19. F 2, F L in the Dipole Model E.C. Aschenauer PheniX-Hardware Workshops Dec. 2010 19 Proton: Nucleus: 2,L 2 GeV 2 F2F2 FLFL

20. x recall: RHIC pp DIS & pp low x behavior unconstrained no reliable error estimate for 1 st moment (entering spin sum rule) find DSSV global fit de Florian, Sassot, MS, Vogelsang positive  g pQCD scaling violations what can be achieved for Δg? E.C. Aschenauer 20 PheniX-Hardware Workshops Dec. 2010

21. strategy to quantify impact: global QCD fit with realistic toy data DIS data sets produced for stage-1 [5x50, 5x100, 5x250, 5x325] and 20x250, 30x325 DIS statistics “insane” after 1 month of running (errors MUCH smaller than points in plots) W 2 > 10GeV 2 polarized DIS and impact on Δg(x,Q2) E.C. Aschenauer 21 PheniX-Hardware Workshops Dec. 2010

22. how effective are scaling violations at the EIC… DSSV+ includes also latest COMPASS (SI)DIS data (no impact on DSSV Δ g) χ 2 profile slims down significantly already for EIC stage-1 (one month of running) with 30x325 one can reach down to x ≈ 3×10 -5 (impact needs to be studied) Sassot, MS what can be achieved for Δg? – cont’d E.C. Aschenauer 22 PheniX-Hardware Workshops Dec. 2010

23. what about the uncertainties on the x-shape … … wow – cool! even with flexible DSSV x-shape we can now determine up to ± 0.07 work in progress: try weird x-shapes below x = 10 -4 to improve/check error estimate Sassot, MS what can be achieved for Δg? – cont’d E.C. Aschenauer PheniX-Hardware Workshops Dec. 2010 23

24. Separate Sivers and Collins in SIDIS E.C. Aschenauer RSC-Meeting, Berkley, November 2009 24 angle of hadron relative to initial quark spin (Sivers) angle of hadron relative to final quark spin (Collins) Sivers Collins SIDIS allows to study subprocesses individually

25. Sivers in SIDIS E.C. Aschenauer PheniX-Hardware Workshops Dec. 2010 25 Th. Burton

26. Kinematic Plane E.C. Aschenauer PheniX-Hardware Workshops Dec. 2010 26 Need to study hadronic method to increase y acceptance

27. Lepton Kinematics E.C. Aschenauer PheniX-Hardware Workshops Dec. 2010 27 Follow Hera Convention: Hadron beam positive z (=>  = 0 o )  Lepton beam negative z =>  = 180 o )

28. Hadron Kinematics E.C. Aschenauer PheniX-Hardware Workshops Dec. 2010 28

29. Kinematics of elastic diffraction E.C. Aschenauer PheniX-Hardware Workshops Dec. 2010 29 4x250 4x100 4x50 no cuts: cuts: Q2 > 0.1 GeV && y < 0.9 GeV decay products of  & J/ψ go more and more forward with increasing asymmetry in beam energies

30. Diffractive Physics: p’ kinematics PheniX-Hardware Workshops Dec. 2010 30 4 x 100 t=(p 4 -p 2 ) 2 = 2[(m p in.m p out )-(E in E out - p z in p z out )] 4 x 50 4 x 250 ? Diffraction: E.C. Aschenauer recoil protons and break-up particles from Au need dedicated forward detectors

31. What can we detect E.C. Aschenauer PheniX-Hardware Workshops Dec. 2010 31 4x50 p e : 0-1 GeV p e : 1-2 GeV p e : 2-3 GeV p e : 3-4 GeV 4x100 central arm unidentified North  arm only muons Forward upgrade identified hadrons 5 GeVx50GeV 20 GeV x 250 GeV No dependence on hadron beam energy Q 2 >0.1GeV 2 4GeV  >5 o 10GeV  >2 o 20GeV  >1 o New PheniX has close to full coverage for scattered lepton

32. Summary  Good electron and hadron PID is essential to access a lot of unique physics in pp, dA and ep/eA collisions  Symbiosis between hadron and DIS program  We should allow for this physics in the new PHENIX detector  Only a small fraction of physics, which needs PID was discussed  Did not talk about  Charm and Bottom physics  Polarized and unpolarized strangeness physics  ……  Need to still make detailed simulations to understand the performance/requirements in detail  What are the requirements from AA for PID and the forward endcap spectrometer E.C. Aschenauer PheniX-Hardware Workshops Dec. 2010 32

33. E.C. Aschenauer PheniX-Hardware Workshops Dec. 2010 33 BACKUP

34. 2 4 6 8 10 2.5 m 3.5 m 1214 90 mm 5.75 m 16 IP Dipole: 2.5 m, 6Tm  =18 mrad 4.5 m  =18 mrad  =10 mrad Estimated  * ≈ 8 cm  =44 mrad 6.3 cm ZDC p c /2.5 15.7 cm 6 mrad 11.2 cm 4.5 cm neutrons p c /2.5 IP configuration for eRHIC Nice design for protons from exclusive reactions and nuclear breakup particles p t > 1.5GeV  main detector 0.1 MeV < p t < 1GeV after dipole E.C. Aschenauer 34 PheniX-Hardware Workshops Dec. 2010

35. 0.44843 m Q5 D5 Q4 90.08703 m 10 mrad 0.39065 m 60.0559 m 10 20 30 0.333 m IR Design E.C. Aschenauer 35 4 m 4.5  =18 mrad 5.75 m 5.75 cm 11.9 m 17.65 m  =27.194 mrad 30 GeV e - 325 GeV p Or 125 GeV/u ions Dipole to separate p/A beam from “recoil”/breakup particles eRHIC - Geometry high-lumi IR with β*= 8cm, l*=4.5 m and 10 mrad crossing angle © D.Trbojevic PheniX-Hardware Workshops Dec. 2010

36. 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 F 2 A, F L A, F 2c A, F Lc A, F 2 p, F L p,………  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 (  -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., R eA, azimuthal distributions, jets E.C. Aschenauer PheniX-Hardware Workshops Dec. 2010 36

37. What will the current PheniX see PheniX-Hardware Workshops Dec. 2010 37 4x100 p e : 0-1 GeV p e : 1-2 GeV p e : 2-3 GeV p e : 3-4 GeV 4x100 Current PheniX detector not really useable for DIS acceptance not matched to DIS kinematics E.C. Aschenauer