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Resonances from Jets

Resonances from Jets. Christina Markert University of Texas at Austin. Introduction Resonances in Medium Resonances from Jets Conclusions. Resonance Production in Heavy Ion Collisions. Temperature. Shuryak QM04. Quark Gluon Plasma. partons.

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Resonances from Jets

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  1. Resonances from Jets Christina Markert University of Texas at Austin • Introduction • Resonances in Medium • Resonances from Jets • Conclusions Christina Markert, UT Austin

  2. Resonance Production in Heavy Ion Collisions Temperature Shuryak QM04 Quark Gluon Plasma partons 1.) Most resonances (u,d,s) are formed when partonic matter transitions back into hadronic matter 2.) Formation of resonances in hadronic matter due to regeneration 3.) Resonances created from a jet within the QGP phase (mixed dof Phase)  potentially survive in partonic matter (QGP) Tc T Freeze hadrons QGP Pre equili- brium Mixed Phase Hadron gas Hadron Gas 1.) 2.) Mixed dof 3.) Baryochemical potential Ti Tc Tchem Tkin Christina Markert, UT Austin

  3. Tchemical Tchemical Bulk High pT dN/dpT 99% pT[GeV/c] 0 ~2 Time Evolution of Heavy Ion Reactions late early Dt > 3-5 fm/c resonances Pre-equilibrium : < 1fm/c Partonic medium (QGP) tQGP ~ 5 fm/c Hadronic medium (HG) tHG~ 5 fm/c t ~ 10 fm/c 2 particle correlation Christina Markert, UT Austin

  4. Resonances Interact with Hadronic Medium p L* K p p L* K Resonances below pT < 2 GeV/c interact with hadronic medium(bulk matter) Hot and dense medium time Marcus Bleicher and Jörg Aichelin Phys. Lett. B530 (2002) 81 + private communication Christina Markert, UT Austin

  5. Resonance Suppression [1] P. Braun-Munzinger et.al.,PLB 518(2001) 41, priv. communication [2] Marcus Bleicher and Jörg Aichelin Phys. Lett. B530 (2002) 81. M. Bleicher and Horst Stöcker J. Phys.G30 (2004) 111. Life-time [fm/c] : K(892) = 4.0 S(1385) = 5.7 L(1520) = 13  (1020) = 45 [1] [2] Phys. Rev. Lett. 97 (2006) 132301 Christina Markert, UT Austin

  6. K and p Fluctuations STAR Preliminary A Lordanova SQM2007 G. Torrieri, R. Bellwied, C. Markert, G. Westfall arXiv:1001.0087 • Fluctuations of K and p from K* scattering in hadronic phase • Reconstructed K* resonances are from non-scattered decay particles (K.p) • Indication of small hadronic phase, but errors are still large ? • L*/L is better observable, more sensitive to hadronic lifetime • due to smaller regeneration cross section (in progress) Christina Markert, UT Austin

  7. Resonances at lower Energies (SPS) G. Torrieri and J. Rafelski, Phys. Lett. B509 (2001) 239 NA49 Preliminary Model:HGM Becattini et al. PRC73 (2006) 044905 RHIC: T= 160 MeV =>  > 4 fm/c SPS: T=160 MeV =>  > 6 fm/c (lower limit !!!) Hadronic lifetime at SPS longer than at RHIC energies? UrQMD v2.3 UrQMD Marcus Bleicher and Jörg Aichelin Phys. Lett. B530 (2002) 81-87. M. Bleicher and Horstn Stöcker Phys.G30 (2004) 111. (S.Vogel) M. Mitrovski SQM2009 UrQMD  hadronic lifetime Christina Markert, UT Austin

  8. The main Feature of Quantum Chromodynamics • Confinement • Free quarks are not observed in nature. • Asymptotic freedom • Under such conditions quarks and gluons appear to be quasi-free. • (Hidden) chiral symmetry • Connected with the quark masses • In the small coupling limit (some) quarks have small mass - current mass • When confined quarks have a large dynamical mass - constituent mass • Hadron Mass: • Higgs mass (current mass) • + • QCD mass (dynamical mass) • Approaching ‘asymptotic freedom’ • Dynamical mass decreases • Hadron mass is decreasing Chiral symmetry restored Measure Resonances  without interaction in hadronic medium B.Mueller (2004): New Discoveries at RHIC Christina Markert, UT Austin

  9. Di-electron Measurement (PHENIX) p+p Au+Au minimum bias Phys.Lett.B670:313-320 arXiv:0706.3034 A significant excess is observed at low mass in Au+Au minimum bias Alberica Toia QM2008 Low-Mass Continuum:enhancement 150 <mee<750 MeV: 3.4±0.2(stat.) ±1.3(syst.)±0.7(model) see WWND10: Sarah Campbell Elena Bratkovskaya Christina Markert, UT Austin

  10. Resonances from Jets to Probe Chirality We want early produced resonances and decay in chirally restored medium  resonances from jets CM, R. Bellwied, I.Vitev, Phys.Lett.B669:92-97,2008 hadrons/ resonances 1.) Most resonances (u,d,s) are formed when partonic matter transitions back into hadronic matter 2.) Formation of resonances in hadronic matter due to regeneration 3.) Resonances created from a jet within the QGP phase (mixed dof Phase)  potentially survive in partonic matter (QGP) partonic medium hadrons/ resonances QGP Pre equili- brium Mixed Phase Hadron gas 1.) 2.) Mixed dof 3.) Ti Tc Tchem Tkin Christina Markert, UT Austin

  11. Formation of Hadronic Resonances (from jets) • light cone variables: • large z (=ph / pq) • = Resonance is leading particle in jet • shortens formation time • color neutral pre-hadron (resonance) 10 GeV/c f(1020) t ~ 4.5 fm/c CM, R. Bellwied, I.Vitev, Phys.Lett.B669:92-97,2008 t ~ 1.5 fm/c Heavier particles of same momentum formed earlier High momentum particles formed later Christina Markert, UT Austin

  12. Formation Time of Resonances • Resonance needs to decay in the partonic or the dense hadronic medium:  short lived resonances • reconstruction difficult • (broad states): • Resonances are medium modified • short lifetime modified K*, L*, S*, f are good candidates Markert, Bellwied, Vitev Phys.Lett.B669:92-97,2008 RHIC LHC lifetime At LHC the momentum range of resonances decaying inside QGP is extended to higher momentum due to longer QGP lifetime Holt & Haglin, J. Phys. G31 (2005) f(1020): RHIC pT= [3-10] GeV LHC pT=[2-20] GeV Christina Markert, UT Austin

  13. Triggered Resonance (STAR) Cu+Cu (quadrant correlation analysis) side 1 near away side 2 Hadron trigger pT > 3 GeV f(1020) asso pT =1-2 GeV near away Width: 6.0±0.7 MeV First bin in delta phi thermal resonances Φ(1020) Φ(1020) hadron-resonance correlation M(K+ K-) GeV/c2 HQ2008 Width: 7.2±0.9 MeV • No evidence for mass shifts and • width broadenings on the away-side • Most f(1020) are from thermal medium (90%) • Need higher pT resonances  lot of events needed M(K+ K-) GeV/c2 Christina Markert, UT Austin

  14. Resonances at the LHC (ALICE) ALICE EMCal Physics Performance Report Statistics for 1 month Pb+Pb data Christina Markert, UT Austin

  15. side 1 near away side 2 Resonances from jets in ALICE Statistics in Pb+Pb pythia jet trigger pT = [50,60] GeV/c resonance pT > 4 GeV/c Christina Markert, UT Austin

  16. side 1 near away side 2 Resonance ratios in four quadrants no interaction with hadronic medium for high pT and jet triggered resonances Pythia K*/K K*/K Christina Markert, UT Austin

  17. K* Fragmentation Function Modification ALICE EMCal Physics Performance Report Statistics for 1 month Pb+Pb data Christina Markert, UT Austin

  18. Conclusions Low pt resonances are sensitive to hadronic medium (lifetime). High pt resonances from jets are sensitive to early medium and might probe Chiral Symmetry Restoration. Measure modification of resonance FF. Christina Markert, UT Austin

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