Jet/Photon/Hadron Correlations at RHIC-PHENIX Kenta Shigaki (Hiroshima University ) for the X Collaboration International Workshop on High pT Physics 2012 October 22, 2012 Central China Normal University, Wuhan, China

HPT’12 – Jet/Photon/Hadron Correlations at RHIC-PHENIX – K.Shigaki presentation outline direct g as established ultimate trigger direct g–hadron correlation quark energy loss, fragmentation, (re-)distribution enhancement/suppression w.r.t. “initial” quark energy away (jet) side angular shape reconstructed jet sPHENIX summary and concluding remarks Oct.22, 2012 HPT’12 – Jet/Photon/Hadron Correlations at RHIC-PHENIX – K.Shigaki

direct g : ultimate trigger particle non-modified reference trigger cf. both sides modified in jet–jet, jet–h, h–h no surface bias trigger g energy  partner energy in leading order dominantly tagging (u-, d-)quark-jets though with additional electro-magnetic a Oct.22, 2012 HPT’12 – Jet/Photon/Hadron Correlations at RHIC-PHENIX – K.Shigaki

direct g : solid p+p baseline higher statistics dataset pT reach extended by ~ 2 precision improved by > 2 more precise isolated fraction 90% isolation in R < 0.5 possibility to use isolated component PHENIX, arXiv:1205.5533, submitted to PRD isolated / all photon Oct.22, 2012 HPT’12 – Jet/Photon/Hadron Correlations at RHIC-PHENIX – K.Shigaki

direct g : Au+Au analysis finalized 2004 Au+Au data analysis finalized spectra published with better precision systematics (e.g. p0 merging) studied in detail PHENIX, PRL 109, 152302 (2012) Oct.22, 2012 HPT’12 – Jet/Photon/Hadron Correlations at RHIC-PHENIX – K.Shigaki

direct g : established as reference absence of suppression re-confirmed models resulting in suppression looking no longer viable PRL 109, 152302 gdir p0 Oct.22, 2012 HPT’12 – Jet/Photon/Hadron Correlations at RHIC-PHENIX – K.Shigaki

direct g–hadron correlation function of momentum fraction w.r.t. direct g z  pT (hadron) / pT (direct g) x  - log (z) decay g–hadron correlation statistically subtracted direct/inclusive g ratio from new single g analysis decay g–hadron ~ p0–hadron correlation flow modulation included recent statistical improvements combined 2007 and 2010 data sets wider 0–40% centrality bin Oct.22, 2012 HPT’12 – Jet/Photon/Hadron Correlations at RHIC-PHENIX – K.Shigaki

quark energy loss and re-distribution high z (low x) suppressed; low z (high x) enhanced improved statistics “lost” jet also accounted for cf. LHC non effect at z = 1 only within identified jets 0.7 0.9 0.5 0.4 0.3 0.2 0.1 0.05 Oct.22, 2012 HPT’12 – Jet/Photon/Hadron Correlations at RHIC-PHENIX – K.Shigaki

closer look at energy re-distribution wider away (jet) side enhancement at lower z low z high z Oct.22, 2012 HPT’12 – Jet/Photon/Hadron Correlations at RHIC-PHENIX – K.Shigaki

another view: angular shape analysis evolution with away (jet) side angle range rise from high to low z in all integration ranges less low z enhancement in jet “core” region little angle range dependence at high z Oct.22, 2012 HPT’12 – Jet/Photon/Hadron Correlations at RHIC-PHENIX – K.Shigaki

HPT’12 – Jet/Photon/Hadron Correlations at RHIC-PHENIX – K.Shigaki not just vn effect flow effects as background correlations v3, v4 heavily affecting away side structure and residual broadening not explained just with v3, v4, … tested with conservatively large v3, v4 at high pT vn effects mostly canceled in decay g–hadron subtraction higher pT lower pT v2 only Oct.22, 2012 HPT’12 – Jet/Photon/Hadron Correlations at RHIC-PHENIX – K.Shigaki

jet reconstruction in PHENIX Gaussian filter: developed for heavy ion collision backgrounds seedless, cone-like algorythm optimized to find energetic jet core jet axis stabilized against background particles p+p measurement matches well with pQCD Oct.22, 2012 HPT’12 – Jet/Photon/Hadron Correlations at RHIC-PHENIX – K.Shigaki

HPT’12 – Jet/Photon/Hadron Correlations at RHIC-PHENIX – K.Shigaki powerfulness of jet extended kinematic reach surprising centrality dependence in d+Au cf. initial state effects in direct g interesting different systematics between jet and hadron (p0) Oct.22, 2012 HPT’12 – Jet/Photon/Hadron Correlations at RHIC-PHENIX – K.Shigaki

jet and hadron comparison (in d+Au) empirical pT scaling factor <z> = 0.7 fragmentation not obviously modified ref. talk by D.V.Perepelitsa implying fragments as in vacuum after energy loss Oct.22, 2012 HPT’12 – Jet/Photon/Hadron Correlations at RHIC-PHENIX – K.Shigaki

toward complete scenario quark energy loss suppression at high z (low x) enhancement at low z (high x) un-(or-little-)modified fragmentation (tbc in Au+Au) consistent RdAu for jets and hadrons (thermal-like) energy re-distribution wider away (jet) side enhancement in lower z (high x) x Oct.22, 2012 HPT’12 – Jet/Photon/Hadron Correlations at RHIC-PHENIX – K.Shigaki

HPT’12 – Jet/Photon/Hadron Correlations at RHIC-PHENIX – K.Shigaki outlook: sPHENIX high rate capability and large acceptance 106 jets per year above 30 GeV/c 104 direct g per year above 20 GeV/c differential measurements (v2, v3, …) controlled geometry measurements (A+B, U+U) precise control measurements (p+p, d+Au) Oct.22, 2012 HPT’12 – Jet/Photon/Hadron Correlations at RHIC-PHENIX – K.Shigaki

direct g at RHIC/sPHENIX nice overlap with jet and hadron measurements favorable statistics and S/B conditions higher high pT statistics than p0 at RHIC better direct/inclusive g ratio than at LHC Oct.22, 2012 HPT’12 – Jet/Photon/Hadron Correlations at RHIC-PHENIX – K.Shigaki

potential Japan/Asia contributions sPHENIX “baseline” proposal to US-DOE (vertex tracker +) hadron calorimeter + EM calorimeter other funding required for inner(/outer?) detectors charged particle tracking (e.g. silicon trackers) full jet reconstruction energy re-distribution at low z g/p0/e identification (e.g. pre-shower detector) direct g–jet correlation di-electron m identification (inside or outside of calorimeters?) di-muon Oct.22, 2012 HPT’12 – Jet/Photon/Hadron Correlations at RHIC-PHENIX – K.Shigaki

summary and concluding remarks direct g non-suppression in Au+Au re-confirmed ultimate reference trigger for quark energy loss energy loss and re-distribution observed via g–h high z (low x) suppression; low z (high x) enhancement wider away (jet) side enhancement at lower z naïve scenario consist so far, to be tested further measurements w.r.t. initial parton and leading hadron direct g–jet correlation in Au+Au awaited further prospects: reconstructed jet: baseline established in p+p, d+Au sPHENIX for high pT g and hadron w/ high statistics/rate Oct.22, 2012 HPT’12 – Jet/Photon/Hadron Correlations at RHIC-PHENIX – K.Shigaki