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Heavy flavor systematics from PHENIX

Heavy flavor systematics from PHENIX. Craig Ogilvie, Iowa State University On behalf of the PHENIX Collaboration. Complexity of interpreting data from HI collisions Use systematics: spectra, elliptic flow,… Present d+Au, Cu+Cu, excitation function,…

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Heavy flavor systematics from PHENIX

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  1. Heavy flavor systematics from PHENIX Craig Ogilvie, Iowa State University On behalf of the PHENIX Collaboration • Complexity of interpreting data from HI collisions • Use systematics: spectra, elliptic flow,… • Present d+Au, Cu+Cu, excitation function,… • Which leads to the complexity of interpreting d+Au… cogilvie@iastate.edu

  2. Complexity of d(p)+A collisions • Nuclear structure functions • Shadowing, saturation at low-x • Anti-shadowing at moderate, high-x • Initial state scattering • Often modeled as increase in effective kT • Likely largest impact at RHIC where spectra are softer • Possible collective effects • Barbara Jacak’s talk on Wed • Final state energy-loss, absorption,…. • Centrality classification cogilvie@iastate.edu

  3. CNM I: d+Au heavy-flavor at 200 GeV • Non-photonic e, from heavy-flavor decays Phys. Rev. Lett. 109, 242301 (2012) ,  • Significant enhancement • at moderate pT cogilvie@iastate.edu

  4. CNM II: d+Au heavy-flavor at 200 GeV • Non-photonic e, from heavy-flavor decays • Enhancement present in min-bias • Effect not caused by challenges of centrality definition Phys. Rev. Lett. 109, 242301 (2012)  RdA PT (GeV/c) cogilvie@iastate.edu

  5. CNM IV: Forward, backward m from HF decay m m e Forward rapidity suppressed Likely shadowing at low-x in Au Backward rapidity enhanced anti-shadowing at higher x in Au? or increase in <kT> due to initial scattering? cogilvie@iastate.edu

  6. CNM III: Identified hadron spectra in dA Phys. Rev. C 88, 024906 (2013)  Cronin peak: proton ~ > HFeWhy? cogilvie@iastate.edu

  7. CNM II: d+Au heavy-flavor at 200 GeV Phys. Rev. Lett. 109, 242301 (2012)  RdA Does <kT> increase have larger impact when p+p spectrum is soft? spectra = convolution of scattering + fragmentation Or recombination effects in hadronization? Or collective? Or… Opportunity for theory impact PT (GeV/c) cogilvie@iastate.edu

  8. Example with p0RdA • p0calc from I. Vitev • Reasonable reproduction of p0 • Nuclear structure function • Cronin • Large initial state multiple-scattering • Final state Eloss • Need calculations for heavy-flavor RdA Vitev et al., PRD 74 (2006) Phys.Lett. B718 (2012) 482-487  cogilvie@iastate.edu

  9. J/y CNM EPS09 nuclear structure functions plus breakup Reasonable reproduction, misses centrality dependence BUT, charm is enhanced at moderate pT (non-photonic electrons RdA>1) Do these calculations reproduce open charm RdA >1 ? If not, then more effective suppression needed for J/y PRL 107, 142301 (2011) y

  10. Normalize J/y by HF? • J/yat mid-y suppressed @low-pt • Charm is enhanced at moderate pt • (non-photonic electrons RdA>1) • Alternative: use dA HF spectra as baseline? • Question, what axis? pT? RdA J/y Au-going, high-x d-going, low-x PT (GeV/c) Phys. Rev. C 87, 034904 (2013)

  11. Connect d+Au to A+A Phys. Rev. Lett. 109, 242301 (2012) ,  Min-bias collisions 1) Enhancement in d+Au + energy-loss suppression in A+A 2) Models must attempt to reproduce both d+A and A+A cogilvie@iastate.edu

  12. One method to organize results Phys. Rev. Lett. 109, 242301 (2012) ,  Matt Durham Common suppression pattern when normalized by square of RdA Does this take into account impact of initial state increase of <kT>? cogilvie@iastate.edu

  13. Intermediate Cu+Cu: links d+A and Au+Au Peripheral Cu+Cu (yellow) Enhancement ~ central d+Au (blue) cogilvie@iastate.edu

  14. d+Au to Cu+Cu to Au+Au Interplay of two effects CNM increases yield, competes with energy-loss suppression cogilvie@iastate.edu

  15. d+Au to Cu+Cu to Au+Au Higher pT CNM increases yield, stronger energy-loss suppression cogilvie@iastate.edu

  16. Cu+Cu heavy-flavor, forward rapidity Cu+Cu forward y, Au+Au mid-rapidity dAu Large uncertainties: Forward y in central d+Au ~ peripheral Cu+Cu cogilvie@iastate.edu

  17. Additional lever arm: beam energy charged hadrons from Au+Au Phys. Rev. Lett. 109, 152301 (2012)   p0 pT (GeV/c) Dominant energy-loss at high s Transitions to stronger Cronin effect at lower s

  18. Need RdA at lower-beam energy • Not in current RHIC running plan :( • How does RdA change from 200 GeV to 62 GeV • Three beam energies (62, 200 GeV, LHC) constrains interplay of structure function, initial state scattering • RdAcalculations at 62 GeV • pRdA ~ 2 at 62 GeV • pRdA ~ 1.2 at 200 GeV A. AccardiEur. Phys. J. C 43, 121–125 (2005) cogilvie@iastate.edu

  19. Non-photonicelectrons Au+Au 62 GeV Lower beam energy changes interplay of two effects Stronger CNM competing with weaker energy-loss Forthcoming PHENIX publication spectra with smaller systematics comparison with p+p, RAA etc. If your model reproduces 200 GeV and 2.76 TeV heavy flavor RAA Final call for 62 GeV HF RAA prediction

  20. HF v2at lower beam energy HF flow is > 0 at 62 GeV, but uncertainties large cogilvie@iastate.edu

  21. V2 2nd constraint on e-loss Au+Au 200 GeV • Low-pt Charm v2, extent of thermalization of HF • Challenge for theory to reproduce both RAA, v2 Many calculations, theory updatespast few years cogilvie@iastate.edu

  22. One example, P.B. Gossiaux SQM 2013 Elastic + radiative energy loss With running coupling a cogilvie@iastate.edu

  23. Is dpT/pT what we should be plotting for HF? PRC 87, 034911 (2013) Suggestion in spirit of workshop, This is being worked on for HF, but no results available yet cogilvie@iastate.edu

  24. VTX Upgrade @ PHENIX Two layers of silicon pixel detectors Two layers of silicon strip detectors Four layers in endcaps Tracks extrapolate back to collision vertex Displaced vertices  charm (D), beauty (B) Requires ~ 50 mm precision e X Installed 2010-12 De+X Au Au B e+X e X e p0 e+e- cogilvie@iastate.edu

  25. VTX p+p results • DCA data are fit by expected DCA shapes of • Signal components : c  e and b  e (right column) • Background components (left column) charm/bottom assumes PYTHIA spectra b/(b+c)=0.22+-0.06 Fit range: 0.2<|DCA|<1.5(mm) cogilvie@iastate.edu 2012/10/23

  26. VTX p+p results FONLL consistent with b/(b+c) data cogilvie@iastate.edu 2012/10/23

  27. Physics Goal Energy-loss heavy-flavor  understand nature of sQGP • Progress on understanding many details • If a model reproduces a broad range of data • Can we infer any characteristics of QGP? • Either direct via a parameter of model • Diffusion parameter • Or run same dynamical model in a “box”, e.g. radiation + collision Eloss • Infer effective transport parameters • Which characteristics of sQGP are accessible this way and can we communicate this to our fellow physicists? • Maybe too many unsettled aspects yet cogilvie@iastate.edu

  28. Summary • Complexity of interpreting d+Au • Levers: centrality, A, y, s, change impact of • Structure function, initial state scattering, e-loss,… • HF RdAenhancement up to factor of 1.5 • Call for model calculations • Is dAu HF a better baseline for RAA HF and dAu J/y production?? • Complexity of interpreting data from HI collisions • Cu+Cu HF yields smoothly connects dAuto Au+Au • Competition between enhancement + suppression • Change this competition • Au+Au HF data @ 62 GeV, need dAu running at 62 GeV cogilvie@iastate.edu

  29. Backup slides cogilvie@iastate.edu

  30. X-ranges Eskola et al. JHEP 0904 (2009) 065 cogilvie@iastate.edu

  31. RAA of heavy-flavor: from RHIC to LHC Note to Craig add citations cogilvie@iastate.edu

  32. cogilvie@iastate.edu

  33. Charm production at 62 GeV reproduced by FONLL cogilvie@iastate.edu

  34. cogilvie@iastate.edu

  35. cogilvie@iastate.edu

  36. Less bound charmonia in dAu collisions arXiv:1305.5516 All three systems consistent within uncertainties cogilvie@iastate.edu

  37. Less bound charmonia in dAu collisions arXiv:1305.5516 y’ suppression stronger than J/y for more central dAu collisions Stronger effective breakup cross-section? cogilvie@iastate.edu

  38. Photon in dA Phys.Lett. B718 (2012) 482-487 cogilvie@iastate.edu

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