1 Quarkonium Production at J-PARC Quarkonium Production at J-PARC with Unpolarized Proton Beam Quarkonium Production at J-PARC with Polarized Beam and Target Calculations of charm and J/Ψ production from Yuan Feng Jen-Chieh Peng J-PARC Meeting for Spin and Hadron Physics RIKEN, April 7-8, 2008 University of Illinois at Urbana-Champaign Outline

2 Physics with quarkonium production at J-PARC

3 J/ Ψ Production at J-PARC Energies Very few data for J/ Ψ production at GeV Schub et al., Fermilab E789, PR D52 (1995) GeV/c at CERN-PS 70 GeV/c at IHEP

4 Color-Evaporation Model for J/ Ψ Production Gluon-gluon fusion Quark-antiquark annihilation CEM calculations versus data Schuler, Vogt, PL B 387(1996)181

5 J/Ψ Production at 30 GeV At 800 GeV, J/Ψ production is dominated by gluon-gluon fusion At 30 GeV J/Ψ production is dominated by quark-antiquark annihilation J/Ψ production at 30 GeV is sensitive to quark and antiquark distributions

6 Evidence that gluon-gluon fusion is the dominant mechanism at 800 GeV

7 E866 collaboration: PRL 100 (2008)

8 J/ Ψ production at J-PARC could be sensitive to quark/antiquark distributions! Is quark-antiquark annihilation the dominant mechanism at 30 GeV ?

9 Expected J/ Ψ yields and kinematic coverage J/ Ψ yields for a two-month p+d run at 30 GeV protons/spill 50-cm long liquid deuterium target Assume 50 percent efficiency Expected total number of J/ Ψ events: ~ 8x10 6 Broad coverage in x F, x 1, x 2, p T

10 Nuclear Dependence of J/Ψ Production at 30 GeV 30 GeV data would provide an interesting test for the x F -scaling in J/ψ production Very few data exist for negative x F region

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12 Polarization of J/Ψ E866 p + Cu → J/Ψ + x (beam dump) s 1/2 = 38.8 GeV Typical dimuon mass spectrum for various xF, pT, cosθ bins dσ/dΩ ~ 1 + λcos 2 θ (extraction of λ for various x F, p T bins) (PRL 91 (2003) 21180,hep-ex/030801, T. Chang et al.)

13 Polarization of J/Ψ in p + Cu Collision dσ/dΩ ~ 1 + λ cos 2 θ (λ=1: transversely polarized, λ = -1: longitudinally polarized λ = 0, unpolarized) E866 data hep-ex/ λ is small, but nonzero λ becomes negative at large x F No strong p T dependence for λ Polarization of Ψ’ has never been measured

14 Polarization of Υ(1S),Υ(2S+3S) p + Cu →Υ + x (E866 beam-dump data) Dimuon mass spectrum Υ(1S) Υ(2S+3S) Decay angular distributions Brown et al. PRL 86, 2529 (2001)

15 Polarization of Υ(1S),Υ(2S+3S) p + Cu →Υ + x (E866 beam-dump data) λ for D-Y, Υ(1S), Υ(2S+3S) D-Y is transversely polarized Υ(1S) is slightly polarized (like J/Ψ) Υ(2S+3S) is transversely polarized! Analysis of Y polarization in p+p and p+d is underway (nuclear dependence?) Preliminary result shows ψ’ is also transversely polarized! Brown et al. PRL 86, 2529 (2001) λ λ p T (GeV) xFxF

16 Polarized proton beam at J-PARC ? Pol. H - Source 180/400 MeV Polarimeter Rf Dipole 25-30% Helical Partial Siberian Snakes pC CNI Polarimeter Extracted Beam Polarimeter Polarized proton beam at J-PARC with –Polarized H¯ source –RF dipole at 3 GeV RCS –Two 30% partial snakes at 50 GeV Main Ring 30 GeV 50 GeV

17 Large single-spin asymmetry in light meson production in polarized p-p: Sivers, Collins, and/or higher-twist effect? FNAL-E704 E lab = 200 GeV RHIC-STAR  s = 200 GeV Single-spin asymmetry in polarized p-p collision What is the single-spin asymmetry for J/ Ψ production?

18 Single-spin asymmetry in polarized p-p at J-PARC Single-spin asymmetry (A N ) can probe Sivers function –Sivers function in Drell-Yan is expected to have a sign opposite to that in DIS - J/Ψ production could also probe the Sivers function - Much higher statistics could be obtained in J/ Ψ production

19 Double-spin asymmetry in polarized p-p at J-PARC Double-spin asymmetry (A LL ) with longitudinally polarized beam/target in Drell-Yan (and J/Ψ) probe Sea-Quark polarization - J/Ψ production could also probe the Sea-Quark polarization - Much higher statistics could be obtained in J/ Ψ production D-Y A LL at 50 GeV GRSV G-S

20 Double-spin asymmetry in polarized p-p at J-PARC Double-spin asymmetry (A TT ) with transversely polarized beam/target in Drell-Yan (and J/Ψ) probe quark transversity distribution - J/Ψ production could also probe the transversity distribution - Much higher statistics could be obtained in J/ Ψ production PHENIX, s 1/2 =200GeV, 320 pb -1

21 Summary A rich physics program in J/Ψ production can be carried out at the J-PARC using primary proton beam. J/Ψ production at J-PARC energies is expected to be dominated by quark-antiquark annihilation, similar to Drell-Yan but with much larger cross sections. An extensive and exciting program in spin physics can be pursued if polarized proton and polarized targets are available at J-PARC.

22 Following slides are provided by Feng Yuan

23 Another example: Heavy flavor production Heavy quarkonium production (gg channel) –ep scattering No SSA in color-singlet model Final state interaction in color-octet model –pp scattering Only initial state interaction in color-singlet ISI and FSI cancel out in color-octet Open charm or beauty –Different SSAs for charm and anti-charm 2/18/201623

24 Color-singlet model 2/18/ Final state interactions with quark and anti-quark cancel out each other, no SSA in color-singlet model

25 Color-octet model 2/18/ Final state interactions can be summarized into a gauge link to infinity, nonzero SSA

26 pp scattering 2/18/ Color-singlet model: only initial state interaction, non-zero SSA Color-octet model: initial and final state interactions cancel out, no SSA

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28 J/Psi Production at lower energy (JPARC or FAIR) Quark-channel dominates –Color-singlet: only initial state interaction contributes, -1/2Nc relative to Drell-Yan –Color-octet: both initial and final state interactions contribute, -(Nc^2+1)/2Nc relative to DY 2/18/2016 DPN Meeting

29 JPARC prediction Proportional to the sum of u- and d- quark Sivers function: fitted to HERMES data, Vogelsang-Yuan 05 2/18/2016 DPN Meeting Final A_N depends on the weight of the quark-channel contribution

30 Heavy quark SSA 2/18/2016 DPN Meeting ISI: contribute to quark and anti-quark ~1/4Nc FSI: contribute to anti-quark ~2/4Nc FSI: contribute to quark ~(Nc^2-2)/4Nc

31 FAIR at GSI 2/18/2016 DPN Meeting

32 Summary We are in the early stages of a very exciting era of transverse spin physics studies, where the future RHIC, JLAB, JPARC, FAIR, and EIC experiments will certainly play very important roles We will learn more about QCD dynamics and nucleon structure from these studies, especially for the quark orbital motion