Latest QCD and small-x physics results in p+p, d+Au and Au+Au collisions from PHENIX Stefan Bathe Baruch College, CUNY, and RBRC For the PHENIX Collaboration

Latest QCD and small-x physics results in p+p, d+Au and Au+Au collisions from PHENIX Stefan Bathe Baruch College, CUNY, and RBRC For the PHENIX Collaboration

Cold Nuclear Matter R G Pb Q 2 = 1.69 GeV 2 EPS08 EPS09 nDS EKS98 HKN07 low x high x arXiv: Initial state effects – Modification of gluon distribution shadowing anti-shadowing Gluon saturation – Energy loss and broadening Final state effects – Nuclear absorption – Coalescence? Probes: – Photons, hadrons, jets, open and closed heavy flavor – Two-particle correlations 6/18/13h3QCD workshop, ECT*, Trento3

PHENIX Acceptance in d+Au 6/18/13h3QCD workshop, ECT*, Trento4 |  |<0.5 North Muon Arm 1.2<  <2.2 large x in Au < x < 10 0 anti-shadowing small x in Au < x < shadowing medium x in Au x≈10 -2 in Au MPC-S -3.8 <  < -3 smaller x in Au < x < saturation? larger x in Au < x < 10 0 anti-shadowing -2.2<  <-1.2 Sourth Muon Arm MPC-N 3 <  < 3.8 Central Arms

J/  p T broadens (multiple scattering) w/ N coll ; effect stronger at y=0 6/18/13h3QCD workshop, ECT*, Trento PHENIX PRC87, (2013)

J/  p T broadens (multiple scattering) w/ N coll ; effect stronger at y=0 backward y: – only suppressed at lowest p T – then rapid increase mid and forward y: – Much more gradual increase with p T – Very similar in level and shape 6/18/13h3QCD workshop, ECT*, Trento6 PHENIX PRC87, (2013) high x low x

 ’ R dAu Less tightly-bound/larger  ’ more suppressed than J/  in dAu not initial state effect (parton level) Suggests final-state effect (hadron level) 6/18/13h3QCD workshop, ECT*, Trento 7 PHENIX arXiv:

 ’ time in nucleus 6/18/13h3QCD workshop, ECT*, Trento8 Time in nucleus is short at √s = 200 GeV Shorter than bound state formation time! Late final state effect? arXiv:hep-ph/ PHENIX arXiv:

Open Heavy Flavor No issue of final break-up But x less constrained Harder to measure – non-photonic single leptons (from semi-leptonic decays) – no mass peak 6/18/13h3QCD workshop, ECT*, Trento9 Figure from Phys.Lett. B608,69

Open heavy flavor Clear enhancement in Au-going direction sensitive to high-x in Au (anti- shadowing) Suppression in d-going direction sensitive to low-x (shadowing) Enhancement also at mid-rapidity 6/18/13h3QCD workshop, ECT*, Trento10 high x low x

PID hadrons in dAu Large R dA for protons – Simple Cronin effect? – How does parton know it will produce a proton? No species dependence for AuAu/dAu ratio for same N part, coll – Suggests common production mechanism in dAu and AuAu (coalescence?, flow?) Ratio < 1 at high pT – Energy loss in peripheral AuAu? Ratio > 1 at low pT – Participant asymmetry  rapidity shift? Possible effect from different pdf in dAu vs. AuAu 6/18/13 h3QCD workshop, ECT*, Trento11 PHENIX arXiv: |  | < 0.35

High p T  0 and jets Enhancement in peripheral, slight suppression in central Surprisingly strong centrality dependence Competing cold nuclear matter effects? Auto-correlations between high p T processes & centrality measure? Cross check with p+Si (light ion): no centrality selection necessary (RHIC Run 2015 ) 6/18/13h3QCD workshop, ECT*, Trento12

Direct Photons No modification of direct photons in initial hard scattering and PDF compared to p+p at mid-rapidity 6/18/13h3QCD workshop, ECT*, Trento13 PHENIX arXiv:

Two-Particle Correlations Sensitive to – Flow – Initial state correlations 6/18/13h3QCD workshop, ECT*, Trento14

Non-jet correlation in d+Au? mid-rapidity Per-trigger yield Eliminate jet correlations – Subtract peripheral from central –  gap (  >0.48) Symmetric, cosine- like correlation remains 6/18/13h3QCD workshop, ECT*, Trento15 PHENIX arXiv:

Jet-Subtracted Fourier Moments Fourier moments, c n, of jet- subtracted distributions vs. associated p T Significant c 2 No significant c 3 c 2 from HIJING small c 3 consistent with hydro 6/18/13h3QCD workshop, ECT*, Trento16 PHENIX arXiv:

Fourier Moment v 2 6/18/13h3QCD workshop, ECT*, Trento17 Inferred quadrupolar anisotropy v 2 of h +- vs. p T significant v 2 PHENIX arXiv:

Fourier Moment v 2 6/18/13h3QCD workshop, ECT*, Trento18 Inferred quadrupolar anisotropy v 2 of h +- vs. p T v 2 d+Au > v 2 p+Pb PHENIX arXiv:

6/18/13h3QCD workshop, ECT*, Trento19 p+A vs. d+A

Initial State Fluctuations 6/18/13h3QCD workshop, ECT*, Trento20 Energy deposition a) nucleus center,  2 = 1 b) overlap region  2 = 0 c) follow shape of overlap  2 ≤ 1 initial energy density distribution Bzdak, Schenke, Tribedy, Venugopalan,

Fourier Moment v 2 6/18/13h3QCD workshop, ECT*, Trento21 Inferred quadrupolar anisotropy v 2 of h +- vs. p T PHENIX arXiv:

Fourier Moment v 2 6/18/13h3QCD workshop, ECT*, Trento22 Inferred quadrupolar anisotropy v 2 of h +- vs. p T v 2 consistent with hydro PHENIX arXiv:

Extending to higher rapidities 6/18/13h3QCD workshop, ECT*, Trento23 CNT-MPC Au-going  = 3.5 high x in Au 3 <  < 3.8 CNT-MPC d-going  = 3.5 low x in Au

6/18/13h3QCD workshop, ECT*, Trento24 First evidence of long range ridge correlations in d+Au collisions at RHIC!

Correlations from Glasma Graphs 6/18/13h3QCD workshop, ECT*, Trento25 Dusling, Venugopalan, , , private communication Significant signal expected at RHIC No quantitative comparison at this point since data not corrected for absolute acceptance

Hydro or Glasma Origin? Eploit versatility of RHIC! 6/18/13h3QCD workshop, ECT*, Trento26 PHENIX requesting 3 He+Au, d+Au, p+Au in 2015 with increased acceptance (VTX+FVTX+MPC-EX) Glauber MC, Gaussian E distribution,  = 0.4 fm

Upgrades 6/18/13h3QCD workshop, ECT*, Trento27

VTX+FVTX Improves mass resolution / suppresses background  ’ at forward/backward rapidity 6/18/13h3QCD workshop, ECT*, Trento28

MPC-EX Upgrade Direct photons at low and high x in Run /18/13h3QCD workshop, ECT*, Trento < |  | < 3.8

Conclusions and Outlook Quarkonia – evidence for (expected) shadowing & anti-shadowing – p T dependence challenges models –  ’ break-up not simply size effect – FVTX upgrade for forward/backward y Heavy Flavor – parton multiple scattering (Cronin effect) PID hadrons – Large Cronin effect for protons – Species-independence of AA/pA ratio suggests common production mechanism  0 /jet trend with centrality remains mysterious – p + light ion in Run 2015 No strong evidence for direct photon modification at mid-y – MPC-EX upgrade in Run 2015 Two-particle correlations – Significant non-jet correlations – Correlations persist with very large  gap – Consistent with flow (question of applicability) – Correlations also expected from glasma graphs 6/18/13h3QCD workshop, ECT*, Trento30

d+Au N coll distribution 6/18/13h3QCD workshop, ECT*, Trento31

d+Au dN ch /d  6/18/13h3QCD workshop, ECT*, Trento32 PHOBOS PRC 72,

Polarized p+A: A N p+Au /A N p+p 6/18/13h3QCD workshop, ECT*, Trento33 Kang, Yuan, Phys.Rev., D84:034019, 2011

Outline J/y pT broadening: – larger at mid-rapidity y’ suppression: – larger than for J/y – time in nucleus short open HF RdA – Enhanced at mid-rapidity and backward – Suppressed at forward rapidity PID hadrons – Large Cronin for p – Species-independent ratio of dAu/AuAu_peri 6/18/13h3QCD workshop, ECT*, Trento34 P0, jets: – enhancement in peri Direct g – No modifiaction 2-p correlations at mid- rapidity – Double ridge – Large v2 2-p correlations large h gap – Double ridge