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pA@LHC

pA@LHC. CERN, June 4-8, 2012 . Use of pA for benchmarking AA collisions. Xin -Nian Wang Central China Normal University & Lawrence Berkeley National Laboratory. Any progress between 2002-2012?. INT/RHIC Winter Workshop 2002 on First Two Years of RHIC: Theory versus Experiments

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pA@LHC

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  1. pA@LHC CERN, June 4-8, 2012 Use of pA for benchmarking AA collisions Xin-Nian Wang Central China Normal University & Lawrence Berkeley National Laboratory

  2. Any progress between 2002-2012? INT/RHIC Winter Workshop 2002 on First Two Years of RHIC: Theory versus Experiments December 13 - 15, 2002 Institute for Nuclear Theory, Seattle, Washington

  3. Any progress between 2002-2012? INT/RHIC Winter Workshop 2002 on First Two Years of RHIC: Theory versus Experiments December 13 - 15, 2002 Institute for Nuclear Theory, Seattle, Washington

  4. pA versus AA @RHIC RBRC Workshop on: New Discoveries at RHIC, May 15, 2004

  5. 2002 déjà vu?

  6. Benchmarking AA collisions Cold Nuclear Matter (CNM) effects: • Gluon saturation and nuclear shadowing • Transverse momentum broadening • Parton energy loss in CNM • modified beam PDF • Parton energy loss in hadronic phase • Color flow and hadronization

  7. Multiple scattering in cold nuclear matter DIS of large nuclei DY production in pA

  8. Twist expansion of Multiple Scattering .... k p Leading twist (LH) Higher twist

  9. Liang & XNW (2007)

  10. Leading-twist partondistribution in DIS .... k p Belitsky, Ji and Yuan (2002)

  11. Jet Transport

  12. pT broadening

  13. pT broadening in DIS and DY eA HERMES (2007) DY in pA E866

  14. Complete LO up to twist-4 DIS Gao. Liang & XNW (2010) Song, Gao, Liang & XNW(2011)

  15. Parton energy loss in cold nuclear matter DIS of large nuclei DY production in pA

  16. Leading Twist Drell-Yan Factorization: Separation of short- from long-distance NLO partonic diagram to PDF, LO + NLO collinear part Scaling violation – DGLAP evolution

  17. Annihilation-like processes (q+gq) • Double scattering: … • Single-triple interference: …

  18. Compton-like processes (g+gq) • Double scattering: … • Single-triple interference: …

  19. LPM interference in DY • Final result for particular example Hard-Hard Soft-Hard 19

  20. Medium modified projectile PDF • Modified quark distribution - Vacuum + Medium Modified splitting function • Modified DGLAP evolution

  21. Quark-gluon correlation functions • “factorized” gluon-quark correlation function • Jet transport parameter 21

  22. Modified fragmentation function in DIS Guo, XNW 2000

  23. Modified DGLAP Equations Modified splitting functions

  24. DIS of large nuclei Deng & XNW (2010)

  25. Nuclear effects in Drell-Yan Energy loss VS. Shadowing (FNAL-E866 ELab = 800 GeV) 25

  26. Parton energy loss in Drell-Yan Energy loss VS. Shadowing (FNAL-E906 ELab = 120 GeV) FNAL-E906 provide unambiguous measurement of initial state energy loss 26

  27. pT broadening in pAcollisions XNW, Phys. Rev. C61 (2000) 064910

  28. pT broadening in pA collisions XNW, Phys. Rev. C61 (2000) 064910 Eskola, Paukkunen & Salgado JHEP 0904 (09)065

  29. pT broadening or anti-shadowing? Talk by IlkkaHelenius

  30. pT broadening in HIJING2.1 kT kick in p+A collisions: KT broadening of initial and final partons, with Gaussian distribution Multiple scattering Energy dependence of the width in Gaussian distribution

  31. Shadowing in HIJING Nuclear shadowing: Li & XNW, Phys.Lett.B527, 85(2002) Gluon, fit to the RHIC Quark, fixed on DIS

  32. RpA for final hard partons Cronin Effect at fix pT Shadowing suppress RpAat low pT region (small x region) There is suppression at large pT?

  33. Hard versus soft interaction 1st Hard Scattering 1st Hard Scattering 2nd Hard Scattering 2nd Hard Scattering 1st Soft Scattering 2nd Soft Scattering …… 1st Soft Scattering 2nd Soft Scattering …… De-coherent Hard Collision (DHC) : Soft-Hardde-coupled in multiple scattering in HIJING ……

  34. Hard versus soft interaction For DHC without shadowing, RpA is 1 at large pT

  35. Flavor Correlation in projectile Valence Quark Number Conservation Quark availability is less in multiple scattering … HIJING takes the limiting case: If a quark has been scattered once, only gluon available for latter scattering

  36. Enhanced gluon spectra in pA the Q/G ratio in p+A is smaller at large pT. Gluon fragmentation function is softer than quark

  37. Color flow & hadronization in pA String fragmentation Independent fragmentation Projectile in p+p Projectile in p+A

  38. Hadron spectra modification in pA

  39. Implications of CNM effect on AA All initial CNM effects have strong impact-parameter dependence.In the center of overlapping region where CNM effects are strongest, jet quenching is also the strongest, so final effect in AA is small after jet quenching. Electro-weak particle production in AA are more sensitive to the CNM effects

  40. Jet quenching in hadronic phase of QGP Chen, Greiner, Wang, XNW, Xu （2010） 30% quenching from hadronic phase

  41. Summary Multiple scattering in eA and pA important qhat in cold nuclear matter 0.02 GeV^2/fm Parton energy loss negligible in pA at y=0 Cronin effect from pT broadening is different from anti-shadowing The Cronin peak disappears in CGC because of evolution Parton energy loss during hadronic phase in AA collisions is non-negligible

  42. Summary

  43. Azimuthal Asymmetry

  44. RpA for Final Hadron This flavor correlation suppress RpA of final hadron at large pT Lund Fragmentation

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