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Heavy Flavor Production in p-A Collisions

Heavy Flavor Production in p-A Collisions. Jen-Chieh Peng, Univ. of Illinois at Urbana-Champaign. Heavy Flavor and Quark Matter Workshop, BNL, Dec. 12-14, 2005. J/ Ψ , Ψ ’, Y production cross sections at s 1/2 = 38.8 GeV Comparison with theoretical models

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Heavy Flavor Production in p-A Collisions

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  1. Heavy Flavor Production in p-A Collisions Jen-Chieh Peng, Univ. of Illinois at Urbana-Champaign Heavy Flavor and Quark Matter Workshop, BNL, Dec. 12-14, 2005 • J/ Ψ, Ψ’, Y production cross sections at s1/2 = 38.8 GeV • Comparison with theoretical models • Nuclear effects of J/ Ψ, Ψ’, D and Υ productions • xF and pT dependences • Polarization of J/ Ψ and Υ • Test of NRQCD model • Open charm and open beauty production

  2. FNAL E772 / 789 / 866800 GeV p-A Quarkonium production in P-A Collisions Open-aperture Closed-aperture Beam-dump (Cu) J/Ψ J/Ψ Ψ’ σ(J/ψ) ~ 15 MeV σ(J/ψ) ~ 150 MeV σ(J/ψ) ~ 300 MeV

  3. J/Ψ and Ψ’ cross sections E789 data p + Au → J/Ψ (Ψ’) + x (open aperture) S1/2 = 38.8 GeV K=8 for J/Ψ K=25 for Ψ’ Large discrepancy between the observed J/Ψ (Ψ’) cross sections and the calculations of color-singlet model (Talk by Bodwin)

  4. J/Ψ production cross sections E789 data p + Cu (beam dump) → J/Ψ + x S1/2 = 38.8 GeV Calculations using Color Evaporation Model and CTEQ5L parton distributions (Talk of Vogt) g-g total q-qbar No nuclear effects included Nuclear dependence taken into account

  5. Upsilon production in p+p and p+d at 800 GeV p + d data (E866) 0.1<XF<0.2 0.2<XF<0.3 0.3<XF<0.4 0.4<XF<0.5 0.6<XF<0.7 0.5<XF<0.6 ~ 50,000 Upsilon events

  6. Upsilon cross sections for p+d at 800 GeV Open symbols: p + Cu (E605) Solid symbols: p + d (E866)

  7. CTEQ5L CTEQ4M Would be interesting to compare with NRQCD calculation

  8. (p+d) / (p+p) ratios from E866

  9. Polarization of J/Ψ E866 p + Cu → J/Ψ + x (beam dump) s1/2 = 38.8 GeV (hep-ex/030801, T. Chang et al.) Typical dimuon mass spectrum for various xF, pT, cosθ bins dσ/dΩ ~ 1 + λcos2θ (extraction of λ for various xF, pT bins)

  10. Polarization of J/Ψ in p + Cu Collision dσ/dΩ ~ 1 + λ cos2θ (λ=1: transversely polarized, λ = -1: longitudinally polarized λ = 0, unpolarized) E866 data λ is small, but nonzero λ becomes negative at large xF No strong pT dependence for λ hep-ex/030801 Polarization of Ψ’ is being analyzed

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

  12. 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?) Quarkonium polarization as a possible signature of quark-gluon plasma? (Ioffe, Kharzeev, hep-ph/0306176) λ pT (GeV) λ xF Brown et al. PRL 86, 2529 (2001)

  13. Azimuthal angular distribution for J/Ψ decay

  14. Azimuthal cos2 distribution in the +W Drell-Yan E615 at Fermilab: 252 GeV π- + W Conway et al., PRD39,92(1989) NA10 at CERN: 140/194/286 GeV π- + W Z. Phys. C37, 545 (1988) This azimuthal dependence could arise from the KT-dependent distribution function h1┴

  15. Azimuthal cos2distribution for Drell-Yan processes E866 Very Preliminary Lingyan Zhu, DNP05 talk

  16. Nuclear effects of Quarkonium productions p + A at s1/2 = 38.8 GeV E772 data σ(p+A) = Aασ(p+N) Strong xF - dependence Nuclear effects scale with xF, not x2 What about negative xF?

  17. Nuclear dependence of J/Ψ production at negative XF HERA-B 920 GeV p+W and p+C hep/ex/0506071

  18. PT - broadening for D-Y, J/Ψ and Υ Extract <PT2> from fits to data Δ<PT2> for J/Ψ is larger than for D-Y Similar behavior for J/Ψ and Υ

  19. Comparison between the J/Ψ and Ψ’ nuclear effects p + A → J/Ψ or Ψ’ at s1/2 = 38.8 GeV α(xF) is largely the same for J/Ψ and Ψ’ (except at xF ~ 0 region) ‘Universal’ behavior for α(pT) (similar for J/Ψ, Ψ’; weak s1/2 dependence)

  20. Nuclear effects of open-charm production p + A → D + x at s1/2 = 38.8 GeV E789 open-aperture, silicon vertex + dihadron detection h+h- mass spectrum (after vertex cut) No nuclear effect for D production (at xF ~ 0) D0→ K-π+ Need to extend the measurements to large xF region

  21. Single muon measurement in E866 p+A Thesis of Stephen Klinksiek Targets (Z = -24.0”) 0 = Empty 1 = 0.502 “ Copper 2 = 2.036 “ Beryllium 3 = 1.004 “ Copper Single Muon Trigger Light hadron background is greatly reduced for beam-dump events !

  22. Total Single Muon Events • Passing All Cuts. • Parallel Magnetic Fields • Thin Copper Target From Klinksiek’s talk

  23. D-meson production cross sections in p+Cu VERY PRELIMINARY From Klinksiek’s talk

  24. hep-ex/0506071

  25. Summary • A-dependence of quarkonium production has been reasonably well studied in p-A. Negative xF data are becoming available from HERA-B • Open-charm A-dependence data at a wide range of rapidity is needed for understanding the RHIC A+A open-charm data • Polarization of quarkonium remains a mystery. Additional information from E866 on Ψ’ and upsilon polarization will become available. • New results on heavy quark production are obtained at HERA-B

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