1. PHENIX Heavy-Flavor Results Matt Snowball (LANL) on behalf of the PHENIX collaboration Hard Probes 2015

2. e μ The PHENIX Detector and Heavy Flavor Mid-rapidity Electrons –|η| < 0.35 –Δ ϕ = π –Tracking: DC, PC –eID: RICH, EMcal Forward/Backward- rapidity Muons –1.2 < |η| < 2.2 –Δ ϕ = 2π –~10λ absorber –Tracking: wire chamber –MuID: 5 layers of steel and Iarocci tube plane Measurement of leptons from semi-leptonic decays of D/B mesons –Imperative to understand/subtract background from other lepton sources (hadron cocktail method) 2

3. Heavy Quark Production Heavy quarks produced in early stage of collision –Dominant production mechanism is gluon-gluon fusion at RHIC energy –Experience full evolution of medium in heavy-ion collisions Heavy Flavor is like a tracer moving through the medium, allowing to uniquely probe its evolution 3

4. Heavy Quark Production By changing the size of the system with different nuclei we can follow the evolution of the medium RHIC is well suited to be able to change from small to very large systems Leptons from Heavy Flavor become a unique reference to watch as the system size changes p+p N coll =1 Au+Au N coll ~1000 d+Au Cu+Cu Au+Au We can study evolution of medium effects/modification as system size increases 4

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7. d+Au Results 7

8. mid Electrons at Mid-Rapidity Consistent with scaled p+p results Enhancement at intermediate p T Phys. Rev. Lett. 109, 242301 (2012) e Au d R g from EPS09 Shadowing/Anti-Shadowing Transition 8 Central:Peripheral:

9. fwd bwd Muons at Forward/Backward Rapidity Phys. Rev. Lett. 112, 252301 (2014) Consistent with scaled p+p results Enhancement at backward rapidity μ μ Au d R g from EPS09 Shadowing Region Anti-Shadowing Region 9 Suppression at forward rapidity Central:Peripheral:

10. d+Au: Small But Surprising QGP medium in d+Au collisions? –long-range correlation –elliptic flow arXiv:1404.7461 PeripheralCentral Mid/Backward-y R dA > 1 Forward-y R dA < 1 All-y R dA ≈ 1 10

11. fwdmid Electron-Muon Correlation Phys. Rev. C. 89, 034915 (2014) pQCD-based models agree with the data in p+p collisions Clear suppression of e-mu correlation in d+Au collisions –CNM effects from heavy nuclei e μ Au d R g from EPS09 p+p d+Au 11

12. Explanations? Phys. Rev. C. 88, 024906 (2013) Initial-state effects fail to reproduce the data at both rapidity simultaneously Modification of nPDF Initial k T broadening Cronin enhancement? Initial k T component due to multiple scattering of incoming partons consistent with nPDF modification 12

13. Where is theory on this? pQCD calculation considering incoherent multiple scattering reproduce the enhancement at backward rapidity Phys. Lett. B731 (2014) 51 Radial flow also qualitatively reproduce the enhancement 13 Phys. Lett. B740 (2015) 25 I. Vitev et al A. Sickles

14. Where is theory on this? pQCD calculation considering incoherent multiple scattering reproduce the enhancement at backward rapidity Phys. Lett. B731 (2014) 51 Radial flow also qualitatively reproduce the enhancement Phys. Lett. B740 (2015) 25 14 I. Vitev et al A. Sickles

15. Heavy Flavor Comparison with J/ψ J/ψ: Phys. Rev. C. 87, 034904 (2013) Similar suppression at forward rapidity –Low co-mover density –Same suppression mechanism Different behavior at mid and backward rapidity –Different suppression mechanism Larger nuclear break-up effects at higher-density region d-GoingMid-RapidityAu-Going 15

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18. Cu+Cu Results 18

19. Phys. Rev. C. 90, 034903 (2014) ≈ 182.7 ≈ 5.1 R AA –Significant enhancement in peripheral events –Slight suppression in central events R CP shows a significant suppression –Hot Nuclear Matter effects dominate in central Cu+Cu collisions ≈ 182.7 ≈ 5.1 Cu+Cu Collisions 19 Mid-y Electrons

20. Comparison Between Systems Mid-rapidity HF electrons Very nice agreement between similar systems! Consistent nuclear modification factors between d+Au, Cu+Cu, and Au+Au collisions of similar system size (N part ) CENTRAL d+Au ≈ PERIPHERAL Cu+CuCENTRAL Cu+Cu ≈ MID Au+Au 20 PRC 90 034903 (2014)

21. Evolution of HF e production The nuclear modification factors for HF electrons at mid-rapidity in d+Au, Cu+Cu, and Au+Au Nice trend from smaller systems, d+Au and peripheral Cu+Cu, where enhancement effects are dominating to central Cu+Cu and Au+Au collisions, where suppression effects take over 21 PRC 90 034903 (2014)

22. Future Measurements! PHENIX silicon vertex tracking system Good data samples with the VTX/FVTX of p+p, p+Au, and Au+Au collisions have been collected! –charm/bottom production ratios can be obtained with DCA –charm/bottom separated R AA, R pA can also be obtained –VTX/FVTX results coming for QM15 22

23. Summary 23 Open Heavy Flavor in d+Au Suppression at +y - Consistent with nPDF modification, E-loss Enhancement at mid-y - Beyond nPDF expectations. Cronin? Multiple scattering? Enhancement at -y - Beyond nPDF expectations. Consistent with incoherent multiple scattering Quarkonia in d+Au J/ψ Suppression at +y - Similar behavior to muons from open HF J/ψ Small enhancement at –y - Evidence for extra mechanism → Nuclear break-up? Similar sized systems from d+Au, Cu+Cu, and Au+Au give similar Nuclear Modification Factors FVTX results expected soon! DCA Analyses for HF production ratios

24. BACK UP 24

25. Rapidity Expansion e μ μ Au d MidBwdFwd R g from EPS09 The difference between forward and backward is larger than the expectation from EPS09s 25

26. Rapidity Expansion in Cu+Cu Larger suppression at forward rapidity –may need additional CNM effects (shadowing) at forward rapidity –theoretical calculations considering both hot and cold nuclear matter effects consistent with the data at forward rapidity slightly overestimate the suppression at p T > 3GeV/c, but does not match at p T < 3GeV/c at mid-rapidity HF μ: Phys. Rev. C 86, 024909 (2012) theoretical calculation: R. Sharma, I. Vitev, B.-W, Zhang Phys. Rev. C 80, 054902 (2009) 26

27. Most Central Collisions HF e @ mid-rapidity ≈15.1 ≈182.7 ≈995.4 Phys. Rev. C. 90, 034903 (2014) 27

28. HF e in Au+Au Collisions - 62.4 GeV Enhancement relative to scaled p+p results (ISR data) –Cronin-like enhancement is dominating at lower beam energy? –sizeable difference from the theory considering energy loss arXiv:1405.3301 28