1. Christina Markert 23 rd WWND Montana, Big Sky, Feb 12-17 1 Resonance production in jets Christina Markert University of Texas at Austin Motivation Resonance measurements Time evolution of hadronic phase Chiral symmetry restoration Resonances from jets Summary and a lot of future plans

2. Christina Markert 23 rd WWND Montana, Big Sky, Feb 12-17 2 Lifetime of nuclear medium T chemical  t ~ > 4 fm/c resonances t ~ 10 fm/c 2 particle correlation Partonic phase  < 6 fm/c

3. Christina Markert 23 rd WWND Montana, Big Sky, Feb 12-17 3 Hadronic re-scattering and regeneration Life-time [fm/c] :  = 1.3  ++ = 1.7 K(892) = 4.0  =   (1520) = 13  (1020) = 45 Depends on: hadronic phase density hadronic phase lifetime time chemical freeze-out            signal lost kinetic freeze-out signal measured late decay signal measured rescattering regeneration  e+e+ e-e- signal measured early decay  ++ -- signal measured late decay    e+e+ e-e- signal measured late decay

4. Christina Markert 23 rd WWND Montana, Big Sky, Feb 12-17 4 Resonance suppression in central collisions Phys. Rev. Lett. 97 (2006) 132301 e-Print Archive: nucl-ex/0604019 Resonances from late decay

5. Christina Markert 23 rd WWND Montana, Big Sky, Feb 12-17 5 Resonance decay product re-scattering Decay daughters from low p T resonances re-scatter in hadronic phase Decay daughters from high p T resonances are less affected by hadronic phase Net shift in Resonance signal from early medium Leptonic decay High momentum resonance

6. Christina Markert 23 rd WWND Montana, Big Sky, Feb 12-17 6 Resonance response to medium Tc partons hadrons Baryochemical potential Temperature Quark Gluon Plasma Hadron Gas T Freeze Shuryak QM04 LHC? Resonances below and above Tc:  Chiral symmetry restoration Mass and width of resonances  Hadronic time evolution From hadronization (chemical freeze-out) to kinetic freeze-out.

7. Christina Markert 23 rd WWND Montana, Big Sky, Feb 12-17 7 Chiral symmetry restoration Ralf Rapp (Texas A&M) J.Phys. G31 (2005) S217-S230 VacuumAt T c : Chiral Restoration Measure chiral partners near critical temperature Tc (e.g.  and a 1 ) Data: ALEPH Collaboration R. Barate et al. Eur. Phys. J. C4 409 (1998) a 1  + 

8. Christina Markert 23 rd WWND Montana, Big Sky, Feb 12-17 8 Leptonic resonance reconstruction STAR: Electron hadron separation with Time of Flight upgrade detector STAR Experiment Electronics and detector assembling at UT Austin |1/β-1|<0.03 J.WU QM2006

9. Christina Markert 23 rd WWND Montana, Big Sky, Feb 12-17 9 Mass shift and width broadenings are predicted as influence of medium on resonance spectral function, e.g.: For baryonic and strange resonances M.F.M Lutz (SQM 2001) J.Phys.G28:1729-1736,2002 M.F.M Lutz, E.E. Kolomeitsev, Nucl.Phys.A755:29-39,2005. hep-ph/0501224 For mesonic resonances Ralf Rapp (Texas A&M) J.Phys. G31 (2005) S217-S230  (1520) and  (1385) resonances decay channel change M. Kaskulov et al., nucl-th/0509088 Resonance in a medium (nuclear matter)

10. Christina Markert 23 rd WWND Montana, Big Sky, Feb 12-17 10  (1520) and  (1385) in medium  = 1  0  (1520): ~100 MeV mass shift and (100 MeV width)  (1385): ~40 MeV mass shift and (50 MeV width) Spectral function of  states M.F.M Lutz J.Phys.G28:1729-1736,2002 Resonance in a medium (nuclear matter)

11. Christina Markert 23 rd WWND Montana, Big Sky, Feb 12-17 11 Resonances from jets to probe chirality  Bourquin and Gaillard Nucl. Phys. B114 (1976) T=170 MeV,  T  =0 Leading hadrons Medium away near   In p+p collisions resonances are predominantly formed in jets. Comparison of resonances from jets (no medium) with resonances from bulk (medium) jets ?

12. Christina Markert 23 rd WWND Montana, Big Sky, Feb 12-17 12 Resonances from jets In jet –plane Out of jet-plane In jet-plane    STAR Preliminary near away Study Chiral Symmetry Restoration by comparing resonance production in event classes based on azimuthal distribution: We expect high p T resonances from the away side jet to be medium modified due to the high density and temperature of the partonic and early hadronic medium

13. Christina Markert 23 rd WWND Montana, Big Sky, Feb 12-17 13 Resonances from jets and formation time side 1 side 2 near away Low ptHigh pt Near sideNo medium or late hadronic medium No medium Away sideLate hadronic mediumPartonic or early hadronic medium (depend on formation time) sideLate hadonic mediumEarly hadronic medium K. Gallmeister, T. Falter. Phys.Lett.B630:40-48,2005 General pQCD: Formation time [fm/c] ~ p T [GeV] Specific string fragmentation (PYTHIA) formalism: Gallmeister, Falter, PLB630, 40 (2005) Heavier particles form later, Resonances form earlier Which are the right momenta for trigger and resonance particle?

14. Christina Markert 23 rd WWND Montana, Big Sky, Feb 12-17 14 First attempt  (1020) reconstruction in STAR M inv (K + K - ) Trigger/Event Number of triggers 4.5 M Au+Au 0-20% most central data Leading hadron particle p T > 4.0  trigger/event = 0.12 Associated resonance particle  (1020)  ~ 0.9 GeV   (1020)/event = 0.05

15. Christina Markert 23 rd WWND Montana, Big Sky, Feb 12-17 15  (1020) from same/away side in/out of plane side 1 side 2 near away In Jet-Plane Same Side near In Jet-Plane Away Side away Trigger p T > 4GeV,  (1020) ~ 0.9 GeV All angles Out of Jet-Plane side1 + side2 No mass shifts or width broadenings visible  Expected, since p T of  (1020) is small, need to increase f pT Less signal at the same side compared to away side (20%±10%) M inv (K + K - ) Systematic errors not included !

16. Christina Markert 23 rd WWND Montana, Big Sky, Feb 12-17 16 Hadron - resonance correlation in Au+Au  of h-  (1020) – C h-  (1020) mixed event Pythia 75M events p+p 200 GeV only phi (no background from K+K combinations) QM2006 M.Horner Pythia p+p STAR preliminary ZYAM = zero yield at minimum Hadron trigger p T > 4 GeV  (1020) ~ 0.9 GeV (  need higher p t ) Not corrected for acceptance Systematic BG normalization error not included See Jana’s and Betty’s talk

17. Christina Markert 23 rd WWND Montana, Big Sky, Feb 12-17 17 Conclusion and future plans Hadronic low momentum resonances are affected by hadronic interaction medium Measurement provides lifetime between chemical and thermal freeze out High momentum resonances from jets might be used as a tool to trigger on early produced resonances and test chiral symmetry restoration if they leave the hadronic medium without interaction Need theoretical description of resonance momentum and medium density when decay occur. Study p+p and Au+Au data with different p T selections for associated and trigger resonances in hadron-resonance correlations. Reconstruct resonances in jets with shorter lifetime as  (1020) but sufficient statistics (e.g. K*,  )

18. Christina Markert 23 rd WWND Montana, Big Sky, Feb 12-17 18 EMCal in ALICE Without single jet reconstruction only statistical Analysis possible.  Jet reconstruction Calorimeter necessary Major advantages at the LHC: -Jet energy known, i.e. measure effect as function of fractional momentum -Enhanced statistics in relevant resonance pt-Range (3-10 GeV/c) -Trigger on quark and gluon jets separately