Production, energy loss and elliptic flow of heavy quarks at RHIC and LHC Jan Uphoff with O. Fochler, Z. Xu and C. Greiner Hard Probes 2010, Eilat October 14, 2010 based on arXiv: , &

1Jan Uphoff Production, energy loss and elliptic flow of heavy quarks Hard Probes 2010 Outline Motivation Heavy quark processes in BAMPS Heavy quark production in heavy-ion collisions Elliptic flow and energy loss of heavy quarks Summary

2Jan Uphoff Production, energy loss and elliptic flow of heavy quarks Hard Probes 2010 Motivation Large heavy quark mass >> Λ QCD Charm: M c ≈ 1.5 GeV Bottom: M b ≈ 4.75 GeV D c c _ D _ Heavy quark production at early stage of collision ideal probe for this stage Pre-equil. phase

3Jan Uphoff Production, energy loss and elliptic flow of heavy quarks Hard Probes 2010 BAMPS BAMPS: Boltzmann Approach of MultiParton Scatterings 3+1 dimensional, fully dynamic parton transport model solves the Boltzmann equations for on-shell partons with pQCD interactions Z. Xu & C. Greiner, Phys. Rev. C71 (2005) Phys. Rev. C76 (2007) Implemented processes: No light quarks yet in this calculation, first results on light quarks in BAMPS → talk by Oliver Fochler, Thursday 3pm

4Jan Uphoff Production, energy loss and elliptic flow of heavy quarks Hard Probes 2010 Initial charm in hard parton scatterings 1.LO pQCD: mini-jets 2.NLO pQCD Distributions from R. Vogt 3.PYTHIA Monte Carlo Event Generator for nucleon-nucleon collisions very sensitive on  parton distribution functions  factorization scale  renormalization scale  charm mass Three approaches:

5Jan Uphoff Production, energy loss and elliptic flow of heavy quarks Hard Probes 2010  PYTHIA scaling to heavy-ion collisions with Glauber model (considering shadowing) and energy conservation  Minijets (low p T cut-off at 1.4 GeV)  Color glass condensate H.J. Drescher & Y. Nara, Phys. Rev. C75 (2007) Initial gluon distribution for parton cascade hard partons ~ N bin : number of binary collision soft partons ~ A: number of nucleons

6Jan Uphoff Production, energy loss and elliptic flow of heavy quarks Hard Probes 2010 Charm production in the QGP BAMPS simulation of QGP phase at RHIC Visualization framework courtesy MADAI collaboration, funded by the NSF under grant# NSF-PHY

7Jan Uphoff Production, energy loss and elliptic flow of heavy quarks Hard Probes 2010 Charm production in the QGP at RHIC charm pairs BAMPS Maximum charm production of 3.4 pairs J. Uphoff et al., arXiv: [hep-ph] RHIC

8Jan Uphoff Production, energy loss and elliptic flow of heavy quarks Hard Probes 2010 Charm production in the QGP at RHIC charm quark fugacity Near phase transition charm quark fugacity is above 1 RHIC

9Jan Uphoff Production, energy loss and elliptic flow of heavy quarks Hard Probes 2010 Charm production in the QGP at LHC BAMPS charm pairs LHC bottom pairs Large secondary production → Can even be comparable to initial production charm pairs November run

10Jan Uphoff Production, energy loss and elliptic flow of heavy quarks Hard Probes 2010 Elliptic flow v 2 & nuclear modification factor R AA Elliptic flow Nuclear modifaction factor

11Jan Uphoff Production, energy loss and elliptic flow of heavy quarks Hard Probes 2010 v 2 and R AA for gluons O. Fochler, Z. Xu & C. Greiner, Phys.Rev.Lett.102 (2009) central Au+Au Z. Xu & C. Greiner, Phys. Rev. C 79 (2009)

12Jan Uphoff Production, energy loss and elliptic flow of heavy quarks Hard Probes 2010 Heavy quark elliptic flow v 2 at RHIC only elastic heavy quark processes

13Jan Uphoff Production, energy loss and elliptic flow of heavy quarks Hard Probes 2010 Heavy quark elliptic flow v 2 at RHIC only elastic heavy quark processes PHENIX, arXiv:

14Jan Uphoff Production, energy loss and elliptic flow of heavy quarks Hard Probes 2010 Heavy quark scattering Leading order perturbative QCD: t channel is divergent for small t screening: should be of the order of the Debye mass

15Jan Uphoff Production, energy loss and elliptic flow of heavy quarks Hard Probes 2010 Heavy quark scattering But is there any reason why is exactly equal to ? No! Therefore: is fixed to A. Peshier, arXiv: [hep-ph] P.B. Gossiaux, J. Aichelin, Phys.Rev.C78 (2008) by comparing dE/dx to HTL result beyond logarithmic accuracy Introduce a running coupling constant for all channels

16Jan Uphoff Production, energy loss and elliptic flow of heavy quarks Hard Probes 2010 Heavy quark elliptic flow v 2 at RHIC only elastic heavy quark processes PHENIX, arXiv:

17Jan Uphoff Production, energy loss and elliptic flow of heavy quarks Hard Probes 2010 Fragmentation and Decay Peterson fragmentation Peterson et al., Phys. Rev. D27 (1983) Decay to electrons with PYTHIA Impact of hadronization and decay small

18Jan Uphoff Production, energy loss and elliptic flow of heavy quarks Hard Probes 2010 Heavy quark elliptic flow v 2 at RHIC only elastic heavy quark processes PHENIX, arXiv:

19Jan Uphoff Production, energy loss and elliptic flow of heavy quarks Hard Probes 2010 Heavy quark R AA at RHIC only elastic heavy quark processes PHENIX, arXiv:

20Jan Uphoff Production, energy loss and elliptic flow of heavy quarks Hard Probes 2010 Conclusions & outlook Future tasks: Higher order corrections, gluon radiation for heavy quark scattering Light quarks J/  production Small charm yield during QGP phase at RHIC, not negligible at LHC Negligible bottom yield during QGP phase at LHC LO gluon heavy quark scattering is not sufficient to build up collective flow and R AA Running coupling and improved Debye screening yield results closer to data Full space-time evolution of QGP with charm and bottom quarks Further details on arXiv: , &

21Jan Uphoff Production, energy loss and elliptic flow of heavy quarks Hard Probes 2010 Thank you for your attention.

22Jan Uphoff Production, energy loss and elliptic flow of heavy quarks Hard Probes 2010 Heavy quark scattering cross section

23Jan Uphoff Production, energy loss and elliptic flow of heavy quarks Hard Probes 2010 Heavy quark elliptic flow v 2 at RHIC When does the elliptic flow build up?

24Jan Uphoff Production, energy loss and elliptic flow of heavy quarks Hard Probes 2010

25Jan Uphoff Production, energy loss and elliptic flow of heavy quarks Hard Probes 2010 Heavy quark R AA at RHIC only elastic heavy quark processes PHENIX, arXiv:

26Jan Uphoff Production, energy loss and elliptic flow of heavy quarks Hard Probes 2010 Heavy quark R AA at RHIC PHENIX, arXiv: Central collisions

27Jan Uphoff Production, energy loss and elliptic flow of heavy quarks Hard Probes 2010 Initial conditions for cascade at LHC In agreement with most of LHC predictions (cf. N. Armesto, J.Phys.G35 (2008)

28Jan Uphoff Production, energy loss and elliptic flow of heavy quarks Hard Probes 2010 Energy loss in static medium

29Jan Uphoff Production, energy loss and elliptic flow of heavy quarks Hard Probes 2010 Charm fugacity at LHC