Heavy flavor systematics from PHENIX Craig Ogilvie Iowa

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… 1 cogilvie@iastate. edu Sep 27, 2013

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 k. T �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 2 cogilvie@iastate. edu Sep 27, 2013

CNM I: d+Au heavy-flavor at 200 Ge. V �Non-photonic e, from heavy-flavor decays Phys. Rev. Lett. 109, 242301 (2012) , 3 cogilvie@iastate. edu Significant enhancement at moderate p. T Sep 27, 2013

CNM II: d+Au heavy-flavor at 200 Ge. V �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) Rd. A PT (Ge. V/c) 4 cogilvie@iastate. edu Sep 27, 2013

CNM IV: Forward, backward m from HF decay m e m Forward rapidity suppressed Likely shadowing at low-x in Au Backward rapidity enhanced anti-shadowing at higher x in Au? or increase in <k. T> due to initial scattering? 5 cogilvie@iastate. edu Sep 27, 2013

CNM III: Identified hadron spectra in d. A Phys. Rev. C 88, 024906 (2013) Cronin peak: proton ~ > HFe Why? 6 cogilvie@iastate. edu Sep 27, 2013

CNM II: d+Au heavy-flavor at 200 Ge. V Rd. A Phys. Rev. Lett. 109, 242301 (2012) PT (Ge. V/c) Does <k. T> 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 7 cogilvie@iastate. edu Sep 27, 2013

Example with p 0 Rd. A � p 0 calc from I. Vitev � Reasonable reproduction of p 0 �Nuclear structure function �Cronin �Large initial state multiple- scattering �Final state Eloss �Need calculations for heavy- flavor Rd. A Vitev et al. , PRD 74 (2006) Phys. Lett. B 718 (2012) 482 -487 8 cogilvie@iastate. edu Sep 27, 2013

J/y CNM EPS 09 nuclear structure functions plus breakup Reasonable reproduction, misses centrality dependence BUT, charm is enhanced at moderate p. T (non-photonic electrons Rd. A>1) 1) Do these calculations reproduce open charm Rd. A >1 ? 2) If not, then more effective suppression needed for J/y 9 PRL 107, 142301 (2011) y Sep 27, 2013

J/y Au-going, high-x d-going, low-x Normalize J/y by HF? Phys. Rev. C 87, 034904 (2013) Rd. A 10 PT (Ge. V/c) Sep 27, 2013

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 11 cogilvie@iastate. edu Sep 27, 2013

One method to organize results Phys. Rev. Lett. 109, 242301 (2012) , Matt Durham Common suppression pattern when normalized by square of Rd. A Does this take into account impact of initial state increase of <k. T>? 12 cogilvie@iastate. edu Sep 27, 2013

Intermediate Cu+Cu: links d+A and Au+Au Peripheral Cu+Cu (yellow) Enhancement ~ central d+Au (blue) 13 cogilvie@iastate. edu Sep 27, 2013

d+Au to Cu+Cu to Au+Au Interplay of two effects CNM increases yield, competes with energy-loss suppression 14 cogilvie@iastate. edu Sep 27, 2013

d+Au to Cu+Cu to Au+Au Higher p. T CNM increases yield, stronger energy-loss suppression 15 cogilvie@iastate. edu Sep 27, 2013

Cu+Cu heavy-flavor, forward rapidity d. Au Cu+Cu forward y, Au+Au mid-rapidity Large uncertainties: Forward y in central d+Au ~ peripheral Cu+Cu 16 cogilvie@iastate. edu Sep 27, 2013

Additional lever arm: beam energy p 0 Phys. Rev. Lett. 109, 152301 (2012) charged hadrons from Au+Au p. T (Ge. V/c) Dominant energy-loss at high s Transitions to stronger Cronin effect at lower s 17 Sep 27, 2013

Need Rd. A at lower-beam energy �Not in current RHIC running plan : ( �How does Rd. A change from 200 Ge. V to 62 Ge. V �Three beam energies (62, 200 Ge. V, LHC) constrains interplay of structure function, initial state scattering �Rd. A calculations at 62 Ge. V �p Rd. A ~ 2 at 62 Ge. V �p Rd. A ~ 1. 2 at 200 Ge. V A. Accardi Eur. Phys. J. C 43, 121– 125 (2005) 18 cogilvie@iastate. edu Sep 27, 2013

Non-photonic electrons Au+Au 62 Ge. V 19 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 Ge. V and 2. 76 Te. V heavy flavor RAA Final call for 62 Ge. V HF RAA prediction Sep 27, 2013

HF v 2 at lower beam energy HF flow is > 0 at 62 Ge. V, but uncertainties large 20 cogilvie@iastate. edu Sep 27, 2013

V 2 2 nd constraint on e-loss Au+Au 200 Ge. V �Low-pt Charm v 2, extent of thermalization of HF �Challenge for theory to reproduce both RAA, v 2 Many calculations, theory updates past few years 21 cogilvie@iastate. edu Sep 27, 2013

One example, P. B. Gossiaux SQM 2013 Elastic + radiative energy loss With running coupling a 22 cogilvie@iastate. edu Sep 27, 2013

Is dp. T/p. T 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 23 cogilvie@iastate. edu Sep 27, 2013

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 Installed 2010 -12 X D e+X Au Au B e+X e p 0 e+e- 24 cogilvie@iastate. edu X e Sep 27, 2013

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) 25 cogilvie@iastate. edu 2012/10/23 Sep 27, 2013

VTX p+p results FONLL consistent with b/(b+c) data 26 cogilvie@iastate. edu 2012/10/23 Sep 27, 2013

Physics Goal Energy-loss heavy-flavor understand nature of s. QGP �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 s. QGP are accessible this way and can we communicate this to our fellow physicists? �Maybe too many unsettled aspects yet 27 cogilvie@iastate. edu Sep 27, 2013

Summary � Complexity of interpreting d+Au �Levers: centrality, A, y, s, change impact of �Structure function, initial state scattering, e-loss, … �HF Rd. A enhancement up to factor of 1. 5 �Call for model calculations �Is d. Au HF a better baseline for RAA HF and d. Au J/y production? ? � Complexity of interpreting data from HI collisions �Cu+Cu HF yields smoothly connects d. Au to Au+Au �Competition between enhancement + suppression �Change this competition �Au+Au HF data @ 62 Ge. V, need d. Au running at 62 Ge. V 28 cogilvie@iastate. edu Sep 27, 2013

Backup slides 29 cogilvie@iastate. edu Sep 27, 2013

X-ranges c-cbar SPS Pb+Pb 17 Ge. V X~10 -1 RHIC Au+Au 200 Ge. V X~10 -2 LHC Pb+Pb 5. 5 Te. V X~10 -3 to 10 -4 Eskola et al. JHEP 0904 (2009) 065 30 cogilvie@iastate. edu Sep 27, 2013

RAA of heavy-flavor: from RHIC to LHC Note to Craig add citations 31 cogilvie@iastate. edu Sep 27, 2013

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Charm production at 62 Ge. V reproduced by FONLL 33 cogilvie@iastate. edu Sep 27, 2013

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Less bound charmonia in d. Au collisions ar. Xiv: 1305. 5516 All three systems consistent within uncertainties 36 cogilvie@iastate. edu Sep 27, 2013

Less bound charmonia in d. Au collisions ar. Xiv: 1305. 5516 y’ suppression stronger than J/y for more central d. Au collisions Stronger effective breakup cross-section? 37 cogilvie@iastate. edu Sep 27, 2013

Photon in d. A Phys. Lett. B 718 (2012) 482 -487 38 cogilvie@iastate. edu Sep 27, 2013