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Ridge, Bulk, and Medium Response How to Kill Models and Learn Something in the Process

p 0. p-p 200 GeV. Ridge, Bulk, and Medium Response How to Kill Models and Learn Something in the Process. Jamie Nagle University of Colorado at Boulder. Ridgeology. Bulkeology. Mediumology Bulleology. Multiple Constraints. h. p 0. h.

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Ridge, Bulk, and Medium Response How to Kill Models and Learn Something in the Process

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  1. p0 p-p 200 GeV Ridge, Bulk, and Medium Response How to Kill Models and Learn Something in the Process Jamie Nagle University of Colorado at Boulder Ridgeology Bulkeology Mediumology Bulleology

  2. Multiple Constraints h p0 h Plot shown many times at Quark Matter 2008 RAA IAA c2 /d.o.f. IAA SHARP CONCAVE RAA FLAT CONCAVE Concave conclusion is incorrect because y-axis is really c2/dof. Also, fit is not actually to IAA data.

  3. ASW + Hydrodynamic space-time ~ ~ c2 (total) – c2 (min) ZOWW Au-Au 0-5% Central RAA (p0 pT = 8 GeV), IAA (pTtrig = 8-15 GeV, zT = 0.75) PQM Au-Au 0-5% Central RAA (p0 pT = 8 GeV), IAA (pTtrig = 8-15 GeV, zT = 0.75) RAAorIAA ~ ^ <q> [GeV2/fm] e0 [GeV/fm] The probability of the two measurements being offset from the expectation by 1.5 s (or more), is 1.7% Discriminating ? What do we learn ?

  4. Arnold, Moore, Yaffe (AMY): • q-hat: 4.1 GeV2/fm; • Armesto, Salgado, Wiedemann (ASW): • q-hat: 10.0 – 18.5 GeV2/fm; p/2 0 • Higher Twist (HT): • q-hat: 2.3 - 4.5 GeV2/fm See talk by R. Wei Requires Resolution Without resolution, we cannot extract medium properties. Also, for medium response, one must know how much energy is deposited. How important is realistic space-time geometry? “Hard sphere nuclear overlap differs at most about 10% from a Woods-Saxon geometry.” arXiv:0902.4000v1 What does that mean? I believe the resolution must come from theorists reconciling these pictures. However, we also have new constraints from experiment! Theory-Experiment Collaboration for Hot QCD Matter https://wiki.bnl.gov/TECHQM

  5. Ridge is 1-3% on top of Bulk See talk by J. Chen Medium Response? Basic Properties: 1. pT spectra similar to bulk (or slightly harder) 2. baryon/meson enhancement similar to bulk 3. Scales per trigger like Npart similar to bulk “The Ridge” “Theoretical Free-For-All” Paul Stankus “Theorists, help us Kill your model.” Brian Cole QM08

  6. PHOBOS Preliminary  pt,assoc. > 2 GeV Jet STAR preliminary yield(in  window Trigger pT = 3 …12 GeV Assoc pT = 2 … 4 GeV Trigger pT > 2.5 GeV Assoc pT > 0.035 GeV Ridge STAR Preliminary  window center φΔ ηΔ Trigger pT > 0.150 GeV Assoc pT > 0.150 GeV “Just Right Ridge” “Hard Ridge” “Soft Ridge”

  7. Hard Ridge Comment STAR Preliminary pT,assoc. > 2 GeV pT,trigger. Does the ridge persist up to the highest trigger pT? PHENIX says it might not (PRC78:014901,2008). However, when the ridge / jet << 1, it is hard to see the ridge without a larger Dh window.

  8. Causation Models “Measuring the Collective Flow with Jets” N. Armesto, C.A. Salgado, U.A. Wiedemann, PRL 93, 242301 (2004). Dh RMS ~ 0.5 “Longitudinal Broadening of Quenched Jets in Turbulent Color Fields” A. Majumder, B. Muller, S.A. Bass, PRL 99, 042301 (2007). Dh RMS ~ 0.4 Width in Dh is relatively narrow. Ridge width in Df similar to jets.

  9. Radial Projection STAR Preliminary – Radial Projection PHOBOS plot….. (Jet) = 0.25  0.09 (Ridge) = 1.53  0.41 pt,assoc. > 2 GeV P. K. Netrakanti Both “Hard Ridge” and “Just Right Ridge” show much wider width in Dh (RMS > 1.4). Ridge appears approximately independent of Dh and trigger pT. STAR Preliminary Gaussian s = 0.22 (Jet Peak) Gaussian s = 1.40 (Ridge) The Ridge seems too wide for causation models (IMHO)

  10. Pseudorapidity versus Rapidity Could be an issue at very low pT for protons (in PHOBOS range). Not an issue for “hard ridge” (in STAR range). Thus, causation models really do have a problem.

  11. Momentum Kick Model Scattered parton Jet parton q Effect is almost like initial state kT scatter, but from jet parton. Kick (q) is a tuned parameter and along the direction of the jet parton. One concern is that with an arbitrary y, pT distribution of partons and one q value, can one match any data set. Need to demonstrate they are not arbitrary. C-Y Wong, Phys. Rev. C 78, 064905 (2008).

  12. PYTHIA Jet Width Momentum Kick Model PYTHIA Jet Width STAR Preliminary PHOBOS “Just Right Ridge” Trig 3-4 GeV, Assoc > 2 GeV Trig 4-6 GeV, Assoc > 2 GeV Momentum Kick Model Ridge is too wide in Df. Also, getting wider at large Dh. Df RMS Width Dh Reason is because kick q along jet parton direction. If jet parton at forward angle, less transverse kick.

  13. Auto-Correlation Models fassoc-fradial ftrig-fradial Longitudinal Direction Longitudinal Correlation from underlying event or Glasma flux tubes or other (?)

  14. Jet Induced Ridge fassoc-fradial ftrig-fradial Also note: RAA < 0.01 RAA < 0.1 Longitudinal Direction PHOBOS 0-30% AuAu Trig pT > 2.5 GeV Assoc pT > 35 MeV Model Calculation Jet focused by quenching attenuation and associated particle focused by linear profile radial flow. “Parameter independent calculation reproduces the angular shape, width, and other properties of the ridge.” E. Shuryak, arXiv:0706.3531v1 STAR 0-10% AuAu Trig pT = 3-4, 4-6 GeV Assoc pT > 2 GeV Calculation by Nagle Df (Trigger – Assoc.) Model Calculation Df Width s [radians] Df (Trigger – Radial Vector) Df (Assoc. – Radial Vector) Trigger Attenuation Length l [fm]

  15. Peak Dη Width STAR Preliminary peripheral central What about only radial flow? If both particles were focused by radial flow, one gets a narrower ridge in Df. S.A. Voloshin, nucl-th/0312065v3 S. Gavin, L. McLerran, G. Moschelli, arXiv:0806.4718v3 A. Dumitru, F. Gelis, L. McLerran, R. Venugopalan, arXiv:0804.3858v1 “Soft Ridge” Hard ridge could be some combination of Jet-Bulk and Bulk-Bulk mechanisms. G. Moschelli – see QM Poster

  16. Df P. Sorensen What about only radial flow? Simple calculation assuming Tthermal = 140 MeV and linear boost profile with bmax = 0.7 Calculation by Nagle STAR “Soft Ridge” Assoc. pT > 0.150 GeV PHOBOS “Just Right Ridge” Assoc. pT > 0.035 GeV STAR/PHENIX “Hard Ridge” Assoc. pT > 2 GeV = pions = protons Exact widths in Df are sensitive to these simple parameters.

  17. Fluctuating Initial Conditions + Hydrodynamics NEXUS Initial Conditions + SPHERIO Hydrodynamic Evolution + Cooper-Frye X-coordinate X-coordinate h Y-coordinate But no jets in model, so shape not quite right (?) arXiv:0902.4870v1, J. Takahashi et al.

  18. STAR Preliminary = pions = protons STAR 0-10% AuAu Trig pT = 3-4, 4-6 GeV Assoc pT > 2 GeV pT,assoc. > 2 GeV pT,trigger. Auto-correlation with soft boosted trigger and associated particles looks compelling. However, there is a ridge with trigger pT > 6 GeV. Is it some combination of jet-bulk + bulk-bulk? Prediction for significant widening of ridge in Df for the highest pT triggers. Not seen yet. JN Prediction for narrower Df ridge distribution for protons compared with pions. Look for it! 3 particle correlations (e.g. Dh x Dh) are also interesting, but calculations are not at that point.

  19. Mach Cone Dream Time to Wake Up Pb-Au 17.3 GeV 0-5% CERES Preliminary STAR, PRL102:052302,2009 Au+Au central d+Au Wave Energy at Circle Boundary PHENIX arXiv:0801.4545 f = -900 f = +900 qM = 1.37 ± 0.02 (stat.)± 0.06 (syst.) PERFECT FLUID RESPONSE!

  20. Does the Conical Emission Persist at Highest PT Trigger? STAR, PRL 97 (2006) 162301 d+Au 1/NtrigdN/d(Df) Au+Au 20-40% 1/NtrigdN/d(Df) Au+Au 0-5% 8 < pTtrig < 15 GeV/c, pTassoc>6 GeV/c 1/NtrigdN/d(Df) See Poster A. Adare No evidence at high pT trigger, low pT associated either (but perhaps hidden). At intermediate pT, hadron is likely not a good proxy for the jet axis.

  21. Slide from M. Gyulassy Recent progress on absolute normalization is an attempt to measure background levels, but even then the Assumption of two independent Jet + QGP sources is dubious. More Differential Data Data versus reaction plane, 3 particle correlations, 2+1, … See talk by W. Holzmann I believe experimentalists are paying much more attention. ZYAM is not the issue. If components do not factorize, then we should publish the full correlations (every time).

  22. Renk and Ruppert If one assumes 75-90% of jet energy lost going into response (and also including interaction with flowing medium), one gets general description. arXiv:0901.0230v2 No clear theoretical prediction at this point.

  23. Dijet and then simple boost in one direction (to demonstrate) Pruneau, Gavin, Voloshin, arXiv:0711.1991v2 Again, NEXUS + SPHERIO These soft physics pictures also need to be elevated to realistic full space-time and to confront the full data sets…. Including v1, v2, v3, v4 and fluctuations in these quantities Also, see Poster P. Sorensen arXiv:0902.4870v1, J. Takahashi et al.

  24. Theorists: What do we learn when the model fails? If nothing, then how do we progress? Experimentalists: Publish or Perish ! Fini

  25. Thanks for lots of input and very useful discussions…. Andrew Adare Nestor Amesto Olga Barranikova John Chen Sean Gavin Alex Linden Levy Constantin Loizides G. Moschelli Joern Putschke Lanny Ray Carlos Salgado Anne Sickles Paul Sorensen Paul Stankus Peter Steinberg Jun Takahashi Mike Tannenbaum Fuqiang Wang Edward Wenger C.Y. Wong Nu Xu And more….

  26. EXTRAS

  27. p0 Quenching Factor Single High pT Hadrons Type A, B, C Systematics arXiv:0801.4020 arXiv:0801.1665 What does it mean?

  28. RHIC data RHIC data QGP? sQGP? Constraints and Contradictions ^ +2.1 - 3.2 PQM <q> = 13.2 GeV2/fm +270 - 150 GLV dNg/dy = 1400 +200 - 375 WHDG dNg/dy = 1400 +0.2 - 0.5 ZOWW e0 = 1.9 GeV/fm +0.016 - 0.012 AMY as = 0.280 Each assumes a perfect model with only one unknown parameter. Uncertainties from experiment only! B.Cole, QM08

  29. STAR Preliminary (Quark Matter 2004) Near Side Correlation Trigger pT = 4 - 6 GeV Assoc pT = 0.15 - 4 GeV Trigger pT = 4-6 GeV Assoc pT = 0.15 – 4 GeV (1/Ntrig) dN/d(Dh) Is the ridge really this narrow in Dh? Note that this is the “Just Right Ridge” ! Probably this is not a well constrained fit (?) Dh RMS Dh Df RMS

  30. Soft Ridge Comment yt2 yt1 Explicit soft particle cut applied in proton-proton, but not yet in Gold-Gold.

  31. E_Mach 53.9% E_Diffusion -12.3% E_Neck 57.4% E_Head 1% For the momentum deposited by the jet (in the direction of jet motion) P_Mach 6.5% P_Diff 18.7% P_Neck 73.3% P_Head 1.0%

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