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1 26th Winter Workshop, Ocho Rios, Jamaica January 2010 Christina Markert University of Texas at Austin Introduction Resonances in Medium Resonances from.

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Presentation on theme: "1 26th Winter Workshop, Ocho Rios, Jamaica January 2010 Christina Markert University of Texas at Austin Introduction Resonances in Medium Resonances from."— Presentation transcript:

1 1 26th Winter Workshop, Ocho Rios, Jamaica January 2010 Christina Markert University of Texas at Austin Introduction Resonances in Medium Resonances from Jets Conclusions Christina Markert, UT Austin

2 Temperature Quark Gluon Plasma Hadron Gas T Freeze Shuryak QM04 Baryochemical potential partons Tc hadrons Resonance Production in Heavy Ion Collisions 2.) Pre equili- brium QGP Mixed Phase 3.) 1.) Hadron gas TcTc TiTi T kin T chem Mixed dof 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) 2 26th Winter Workshop, Ocho Rios, Jamaica January 2010 Christina Markert, UT Austin

3 p T [GeV/c] ~20 dN/dp T 99% Bulk High p T Time Evolution of Heavy Ion Reactions T chemical  > 3-5 fm/c resonances  ~ 10 fm/c 2 particle correlation Pre-equilibrium : < 1fm/c Partonic medium (QGP)  QGP ~ 5 fm/c Hadronic medium (HG)  HG ~ 5 fm/c earlylate 3 26th Winter Workshop, Ocho Rios, Jamaica January 2010 Christina Markert, UT Austin

4 Resonances below p T < 2 GeV/c interact with hadronic medium (bulk matter) 4 26th Winter Workshop, Ocho Rios, Jamaica January 2010 Christina Markert, UT Austin Marcus Bleicher and Jörg Aichelin Phys. Lett. B530 (2002) 81 + private communication Hot and dense medium time  p K  p K

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. Phys. Rev. Lett. 97 (2006) 132301 Life-time [fm/c] : K(892) = 4.0  =   (1520) = 13  (1020) = 45 [2] [1] 5 26th Winter Workshop, Ocho Rios, Jamaica January 2010 Christina Markert, UT Austin

6 6 26th Winter Workshop, Ocho Rios, Jamaica January 2010 Christina Markert, UT Austin STAR Preliminary A Lordanova SQM2007 Fluctuations of K and  from K* scattering in hadronic phase Reconstructed K* resonances are from non-scattered decay particles (K.  )  Indication of small hadronic phase, but errors are still large ?   */  is better observable, more sensitive to hadronic lifetime due to smaller regeneration cross section (in progress) G. Torrieri, R. Bellwied, C. Markert, G. Westfall arXiv:1001.0087

7 Resonances at lower Energies (SPS) M. Mitrovski SQM2009 NA49 Preliminary 7 26th Winter Workshop, Ocho Rios, Jamaica January 2010 Christina Markert, UT Austin Model:HGM Becattini et al. PRC73 (2006) 044905 G. Torrieri and J. Rafelski, Phys. Lett. B509 (2001) 239 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  hadronic lifetime UrQMD Marcus Bleicher and Jörg Aichelin Phys. Lett. B530 (2002) 81-87. M. Bleicher and Horstn Stöcker Phys.G30 (2004) 111. (S.Vogel)

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 B.Mueller (2004): New Discoveries at RHIC Measure Resonances  without interaction in hadronic medium 8 26th Winter Workshop, Ocho Rios, Jamaica January 2010 Christina Markert, UT Austin Chiral symmetry restored

9 Di-electron Measurement (PHENIX) A significant excess is observed at low mass in Au+Au minimum bias p+p Au+Au minimum bias Alberica Toia QM2008 Low-Mass Continuum: enhancement 150 <m ee <750 MeV: 3.4±0.2(stat.) ±1.3(syst.)±0.7(model) arXiv:0706.3034Phys.Lett.B670:313-320 9 26th Winter Workshop, Ocho Rios, Jamaica January 2010 Christina Markert, UT Austin see WWND10: Sarah Campbell Elena Bratkovskaya

10 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 2.) Pre equili- brium QGP Mixed Phase 3.) 1.) Hadron gas TcTc TiTi T kin T chem Mixed dof 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 hadrons/ resonances 10 26th Winter Workshop, Ocho Rios, Jamaica January 2010 Christina Markert, UT Austin

11 10 GeV/c  Heavier particles of same momentum formed earlier High momentum particles formed later light cone variables: large z (=p h / p q ) = Resonance is leading particle in jet  shortens formation time  color neutral pre-hadron (resonance)  ~ 4.5 fm/c  ~ 1.5 fm/c CM, R. Bellwied, I.Vitev, Phys.Lett.B669:92-97,2008 11 26th Winter Workshop, Ocho Rios, Jamaica January 2010 Christina Markert, UT Austin

12 Formation Time of Resonances Markert, Bellwied, Vitev Phys.Lett.B669:92-97,2008 At LHC the momentum range of resonances decaying inside QGP is extended to higher momentum due to longer QGP lifetime RHIC LHC  (1020): RHIC p T = [3-10] GeV LHC p T =[2-20] GeV 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*,  *,  *,  are good candidates lifetime Holt & Haglin, J. Phys. G31 (2005) 12 26th Winter Workshop, Ocho Rios, Jamaica January 2010 Christina Markert, UT Austin

13 Triggered Resonance (STAR) Cu+Cu (quadrant correlation analysis) side 1 side 2 near away thermal resonances near away hadron-resonance correlation Hadron trigger p T > 3 GeV  (1020) asso p T =1-2 GeV Width: 7.2±0.9 MeV Width: 7.2±0.9 MeV M(K + K - ) GeV/c 2 First bin in delta phi Width: 6.0±0.7 MeV Width: 6.0±0.7 MeV M(K + K - ) GeV/c 2 HQ2008 No evidence for mass shifts and width broadenings on the away-side Most  (1020) are from thermal medium (90%)  Need higher p T resonances  lot of events needed Φ(1020) 13 26th Winter Workshop, Ocho Rios, Jamaica January 2009 Christina Markert, UT Austin

14 Resonances at the LHC (ALICE) 14 26th Winter Workshop, Ocho Rios, Jamaica January 2010 Christina Markert, UT Austin ALICE EMCal Physics Performance Report Statistics for 1 month Pb+Pb data

15 Resonances from jets in ALICE 15 26th Winter Workshop, Ocho Rios, Jamaica January 2010 Christina Markert, UT Austin side 1 side 2 near away pythia Statistics in Pb+Pb jet trigger p T = [50,60] GeV/c resonance p T > 4 GeV/c

16 Resonance ratios in four quadrants 16 26th Winter Workshop, Ocho Rios, Jamaica January 2010 Christina Markert, UT Austin side 1 side 2 near away no interaction with hadronic medium for high p T and jet triggered resonances side Low p T High p T nearno medium awayhadronic medium  K*/K suppression Partonic or early hadronic medium  if K*/K changes  different modification of resonance FF Pythia K*/K

17 K* Fragmentation Function Modification 17 26th Winter Workshop, Ocho Rios, Jamaica January 2010 Christina Markert, UT Austin ALICE EMCal Physics Performance Report Statistics for 1 month Pb+Pb data

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. 18 26th Winter Workshop, Ocho Rios, Jamaica January 2010 Christina Markert, UT Austin


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