Jet-Hadron Correla/ons Examined with Monte Carlo Models R. Ehlers, - PowerPoint PPT Presentation

1 Jet-Hadron Correla/ons Examined with Monte Carlo Models R. Ehlers, Kirill Lapidus, M. Oliver Yale University, RHI group 01/12/16

2 Introduc/on: Jet-Hadron Correla/ons Azimuthal distribu/on of hadrons 
 in jet-triggered events Near-Side Peak: ‣ surface biased 
 (trigger condi/ons) Away-Side Peak: ‣ longer in-medium path ‣ shower broadening ‣ soQening of the FF Reference: “vacuum” AS peak, measured in pp collisions Kirill Lapidus, Yale

3 Experimental Measurements STAR jet-hadron measurement ‣ hint for the AS peak broadening in AuAu collisions w.r.t. pp reference ‣ systema/cs doesn’t allow for a conclusive statement ‣ data well described by YaJEM On-going analysis: ‣ PbPb at 2.76 TeV J.Phys.Conf.Ser. 446 (2013) 012009 ‣ also feasible with new 5.02 TeV data Need for theore*cal predic*ons! Phys.Rev.Lett. 112 (2014) 12, 122301 Kirill Lapidus, Yale

4 Models JEWEL — explicit pQCD treatment of hard parton scacering on partons of the medium (recoils can be kept or discarded) K. Zapp et al. JHEP 1303 (2013) 080, EPJC C60 (2009) 617 YaJEM — scacering on cons/tuents is not modeled explicitly Hard parton acquires virtuality from the medium: enhanced radia/on ⇒ broadening and soQening of the shower Free parameter 𝜆 must be tuned to reproduce exp. data (R AA ) T. Renk, Phys. Rev. C 84 (2011) 067902 and refs therein Kirill Lapidus, Yale

5 Models JEWEL 2.0.2 YaJEM 1.15 ‣ not an event generator ‣ complete event generator ‣ 1+1 Bjorken-type hydro ‣ in-medium showering rou/ne ‣ hard scacerings from PYTHIA ‣ “user” has to implement own workflow: ‣ hydro input — ε(x,y,z,t) ‣ (1+1) hydro — from JEWEL ‣ (2+1) hydro — superSONIC 
 hcps://sites.google.com/site/revihy/ ‣ hard scacering events 
 (vertex, energy, parton type) Kirill Lapidus, Yale


 
 6 Simula/on and Analysis Setup • AuAu@200 GeV, b = 0 • PbPb@2.76(5) TeV, b = 0 • T in = 370 MeV, T fin = 170 MeV • T in = 470 (500) MeV, T fin = 170 MeV • t in = 0.5 fm 
 • t in = 0.5 fm 
 Jet reconstruc/on: Jet reconstruc/on: • FastJet, an/kt, R = 0.4 • FastJet, an/kt, R = 0.2 • cons/tuents p T > 2 GeV • cons/tuents p T > 3 GeV • hard track p T > 6 GeV • hard track p T > 6 GeV Kirill Lapidus, Yale

7 Hadron R AA AuAu @ 200 GeV ‣ YaJEM tuned to reproduce hadron R AA at RHIC, 𝜆 ~ 2 ‣ JEWEL — default parameters v2.0.2 ‣ Models agree very well in p t range (15,40) GeV Kirill Lapidus, Yale

8 Surface Bias: AuAu @ 200 GeV YaJEM TRANSPARENT MEDIUM ‣ XY-distribu/on of hard scacering ver/ces ‣ w/o jet quenching hard scacering ver/ces 
 are distributed according to the overlap func/on trigger jet direc/on Kirill Lapidus, Yale

9 Surface Bias: AuAu @ 200 GeV YaJEM 2+1 hydro cons/tuents p T > 2 GeV & hard track p T > 6 GeV average hard scacering p t leading jet 20-40 GeV sa/sfying the trigger cond. < X > = − 1.4 fm p t [GeV/c] trigger jet direc/on Kirill Lapidus, Yale

10 Surface Bias: AuAu @ 200 GeV YaJEM 2+1 hydro cons/tuents p T > 2 GeV & hard track p T > 6 GeV cons/tuents p T > 2 GeV & hard track p T > 6 GeV leading jet 10-15 GeV leading jet 20-40 GeV < X > = − 1.4 fm < X > = − 1.66 fm trigger jet direc/on Kirill Lapidus, Yale

11 Surface Bias: AuAu @ 200 GeV YaJEM 1+1 hydro JEWEL 1+1 hydro leading jet 20-40 GeV cons/tuents p T > 2 GeV & hard track p T > 6 GeV < X > = − 2.1 fm < X > = − 1.6 fm ‣ same hydro input used for two models ‣ same qualita/ve picture, details differ Kirill Lapidus, Yale

12 Surface biases for AuAu@200 s = N ver/ces (x < 0) / N ver/ces (x > 0) YaJEM 2+1 ‣ Surface bias depends on the trigger configura/on ‣ Many more variables: R, hard track requirement, … Kirill Lapidus, Yale

13 pp@200 AS fits jet 20-40 GeV p t = (0.2,1) GeV p t = (1,2) GeV p t = (2,3) GeV p t = (4,6) GeV Kirill Lapidus, Yale

14 AuAu@200 AS fits jet 20-40 GeV p t = (0.2,1) GeV p t = (1,2) GeV p t = (2,3) GeV p t = (4,6) GeV Kirill Lapidus, Yale

15 AS widths: AuAu @ 200 GeV cons/tuents p T > 2 GeV & hard track p T > 6 GeV no recoils leading jet 20-40 GeV 𝛕 kt = 2 GeV with recoils ‣ test of the YaJEM implementa/on ✔ ‣ different results for JEWEL with and without recoils Kirill Lapidus, Yale

16 Hadron R AA PbPb @ 2.76 TeV ‣ Model parameters fixed at RHIC energies Kirill Lapidus, Yale

17 Surface Bias: PbPb @ 2.76 TeV JEWEL 1+1 hydro cons/tuents p T > 3GeV & hard track p T > 6 GeV cons/tuents p T > 3GeV & hard track p T > 6 GeV leading jet 15-20 GeV leading jet 20-40 GeV ‣ less pronounced surface bias at LHC Kirill Lapidus, Yale

18 AS widths: PbPb @ 2.76 (5) TeV cons/tuents p T > 3 GeV & hard track p T > 6 GeV leading jet 20-40 GeV PbPb 2.76 TeV PbPb 5 TeV ‣ increased effect to be expected at LHC Kirill Lapidus, Yale

19 Summary and outlook • YaJEM workflow implemented • Jet-hadron correla/ons and surface biases 
 studied with YaJEM and JEWEL • Predic/ons for LHC are made • New high-precision data are awaited • Other observables (dijets, …) • Other models (q-PYTHIA, AdS/CFT MC?) Kirill Lapidus, Yale

20 Backup slides Kirill Lapidus, Yale

21 Jet R AA AuAu @ 200 GeV Kirill Lapidus, Yale

22 Surface Bias: AuAu @ 200 GeV YaJEM 1+1 hydro leading jet 10-15, 2 GeV, 6 GeV leading jet 20-40, 2 GeV, 6 GeV < X > = − 1.8 fm < X > = − 2.1 fm Kirill Lapidus, Yale

23 Jet R AA PbPb @ 2.76 TeV Kirill Lapidus, Yale

24 Hadron R AA PbPb @ 5 TeV Kirill Lapidus, Yale

25 Jet R AA PbPb @ 5 TeV Kirill Lapidus, Yale

26 Medium as seen by a parton AuAu@200, b = 0 𝞈 𝞈 r r Kirill Lapidus, Yale

27 Shower profile q E = 20 GeV, 2 GeV const cut T. Renk Kirill Lapidus, Yale

28 Surface Bias: AuAu @ 200 GeV YaJEM 2+1 hydro cons/tuents p T > 2 GeV & hard track p T > 6 GeV cons/tuents p T > 2 GeV & hard track p T > 6 GeV leading jet 20-40 GeV leading jet 20-40 GeV R = 0.4 R = 0.2 < X > = − 1.66 fm < X > = − 1.75 fm trigger jet direc/on Kirill Lapidus, Yale