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Jozsó Zimányi (1931 – 2006)

Jozsó Zimányi (1931 – 2006). Jozsó Zimányi I met Prof. Zimányi in India in 1984. Member, NA49 and PHENIX Collaborations Nuclear Equation of State with derivative scalar coupling. ALCOR : A Dynamic model for hadronization. Particle ratios in heavy ion collisions.

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Jozsó Zimányi (1931 – 2006)

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  1. Jozsó Zimányi (1931 – 2006)

  2. Jozsó ZimányiI met Prof. Zimányi in India in 1984. • Member, NA49 and PHENIX Collaborations • Nuclear Equation of State with derivative scalar coupling. • ALCOR : A Dynamic model for hadronization. • Particle ratios in heavy ion collisions. • Charmed and strange hadron productions in heavy ion collisions. • Exotic particles in heavy ion collisions. • Quark and hadro-chemistry.

  3. Photon and dilepton production in heavy-ion collisions Bikash Sinha Saha Institute of Nuclear Physics and Variable Energy Cyclotron Centre Budapest July 2007

  4. Contemporary Wisdom(Again?) Lattice Calculation F.Karsch’95 No Quarks: Pure SU(N) gauge theories  Phase transition Second order for N=2  1st order for N=3

  5. QCDnflight quarks  Phase transition 1st order nf3  seems to be continuous for nf =2 Tc  number of partonic degree of freedom in units of the string tension Tc / Tc (nf =2)  150 MeV Tc(nf =0)  160 MeV Glue balls O(1GeV)

  6. QCD Phase Diagram Quark Matter

  7. ( Decay widths ) Chiral Hadrodynamics Mesons, Vector mesons, Baryons No Universal law of m*x Brown – RHO Scaling law does not seem to hold Ie,

  8. Medium effects : (Finite Temp Field th.) P. Roy, S. Sarkar, J. Alam, B.S., Nucl Physics A 653 (1999) S. Sarkar, P. Roy, J. Alam, B. S. Phys. Rev. C (1999) & Annals of Phys 2000 fv Coupling between electromagnetic current & vector meson Field,ω0 Continuim Threshold Should not J. Alam S. Sarkar T. Hatsuda T. Nayak B. S. (2000)

  9. Sarkar et al. NPA 1998 VARIATION OF VECTOR MESON MASS WITH TEMPERATURE

  10. Photons Hadronic matter Quark matter pp->rg qg->qg pr->pg qq->gg w->pg r->ppg pp->hg ph->pg

  11. Light from QGP qq m+m-~ T4 B.S. PLB 1983 m+ q q m- R  / m+m- = const( a, as)

  12. Dileptons Hadronic matter Quark matter w-> e+e- qq->e+e- r-> e+e- qg -> q g* f-> e+e- qq -> g g*

  13. Space time evolution • Relativistic hydrodynamics ∂mTmn = 0 Transverse expansion with boost invariance in the longitudinal direction Equation of state : Bag model for QGP and resonance gas model for hadrons

  14. Isentropic expansion : Hydrodynamics takes care of the evolution of the transverse motion.

  15. Direct Photons at SPS • Alam et al. PRC (2003) 054901 • Data from: Aggarwal et al. (WA98 Collaboration) PRL (2000) 3595

  16. CERES J. Alam, S. Sarkar, T. Hatsuda, J. Phys. G (2004)

  17. Radiation at RHIC J. Alam, J. Nayak, P.Roy, A. Dutt-Mazumder, B.S.: nucl-th/0508043 Jour. Phys. G (2007)

  18. B.S. PLB 1983 Sometime ago it was noted that:“The ratio of the production rates (/+-) and ( o,/+-) from quark gluon plasma is independent of the space time evolution of the fireball”.Universal Signal : (1) (2) (3) Only a function of universal constants.

  19. Thermal Photons Invariant yield of thermal photons can be written as Q  QGP M  Mixed (coexisting phase of QGP and hadrons) H  Hadronic Phase is the static rate of photon production  convoluted over the space time expansion.

  20. Thermal photons from QGP : using hard thermal loop approximation. Again, Collinear equation: Resumming ladder diagrams in the effective theory Thermal photons from hadrons : (i)  (ii)  (with , , ,  and a1, in the intermediate state) (iii)  (iv) ,  and  & Similarly from strange meson sector

  21. Dileptons • Rather similar to photons, dileptons can be efficient probe for QGP – again not suffering from final state interactions. • One has to subtract out contributions from: • (a) Drell–Yan process, • (b) Decays of vector mesons within the life time of the fireball • (c) Hadronic decays occurring after the freeze out. • Invariant transverse momentum distribution of thermal dileptons (e+e- or virtual photons, *): integrated over the invariant mass region:

  22. Consistent with e+e- V(r,w,f) data Dileptons from light vector mesons (, ) &  (Hadronic Sector) : fV(V) :coupling between electromagnetic current and vector meson fields mV and GV are the mass and width of the vector V and w0 are the continuum threshold above which the asymptotic freedom is restored.

  23. The number density as a function of temperature. Effect of mass modification and width modification is shown.

  24. Photons at SPS

  25. Photons at RHIC J. Alam, J. Nayak, P.Roy, A. Dutt-Mazumder, B.S.: J. Phys. G 2007

  26. Di-electrons at RHIC

  27. RESULTS from the ratio: • The variation of Rem (the ratio of the transverse momentum spectra of photons and dileptons) has been studied for SPS, RHIC and LHC. • Simultaneous measurements of this quantity will be very useful to determine the value of the initial temperature of the system. • Remreaches a plateau beyond PT=1 GeV. The value of Rem in the plateau region depends on Ti but largely independent of Tc, vo, Tf and the EOS.

  28. Ratio (Rem) at SPS

  29. Ratio (Rem) at RHIC

  30. Ratio (Rem) at LHC

  31. Ratio (Rem) for pQCD processes FILTERING OUT pQCD PHOTONS

  32. Ratio (Rem) vs. Initial Temperature arXiv:0705.1591 [nucl.th]

  33. OBSERVATIONS: • The medium effect on Rem is negligibly small • Hydrodynamic effects such as viscosity, flow get sort of erased out by observing the ratio, Rem • Equivalently, model dependent uncertainties also get cancelled out through Rem • Contributions from Quark Matter increase with the increase of the initial temperature – • thermal photons mostly for hadronic phase at SPS • thermal photons from RHIC and more so from LHC originate from QGP • Rem flattens out beyond pT ~ 0.5GeV • Rem increases with initial temperature and flattens out beyond Ti ~ 800MeV • In the plateau region: RemLHC > RemRHIC>RemLHC • EOS including quasi particle in the quark matter is being tackled.

  34. The ratio, Rem seems to be insensitive to EOS, medium effects on hadrons, final state effects, Tc, flow. However, it is sensitive to Ti Rem can be used to estimate Ti.

  35. OBSERVATIONS, contd. WHY & HOW Rem (in Born approx.) => At the end Rem still remains by far and large model independent: SPS => RHIC => LHC Thus Rem is a universal signal of QGP, model independent and unique.

  36. In an expanding system, however, Rem involves the superposition of results for all temperatures from Tito Tf, so the effective (average) temperature, Teff will lie between Ti and Tf and We see that is a function of the universal constants and the temperature. Because of the slow (logarithmic) variation as with temperature, one can assume This explains: It is also interesting to note that for as = 0.3, T=0.4GeV, (DM)2 ~ 1 (Mmax=1.05, Mmin=0.28), we get: Rs~ 260. This is comparable to Rem obtained in the present calculation.

  37. WHAT DO WE EXPECT at LHC

  38. Photons and di-electrons in the ALICE experiment Electron-pairs Photons

  39. ALICE Experiment at LHC Muon chambers PMD Modules MUON arm m-pairs PMD photons

  40. LOOKING FORWARD TO THE VERIFICATION OF THE UNIVERSAL SIGNATURE: /e+e- as well asg/m+m- at the Large Hadron Collider

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