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Flavor Dynamics Michael Murray for BRAHMS

Flavor Dynamics Michael Murray for BRAHMS. C. Arsene 12 , I. G. Bearden 7 , D. Beavis 1 , S. Bekele 12 , C. Besliu 10 , B. Budick 6 , H. B ø ggild 7 , C. Chasman 1 , C. H. Christensen 7 , P. Christiansen 7 , H.Dahlsgaard 7 , R. Debbe 1 ,

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Flavor Dynamics Michael Murray for BRAHMS

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  1. Flavor DynamicsMichael Murray for BRAHMS C. Arsene12, I. G. Bearden7, D. Beavis1, S. Bekele12, C. Besliu10, B. Budick6, H. Bøggild7, C. Chasman1, C. H. Christensen7, P. Christiansen7, H.Dahlsgaard7, R. Debbe1, J. J. Gaardhøje7, K. Hagel8, H. Ito1, A. Jipa10, E.B.Johnson11, J. I. Jørdre9, C. E. Jørgensen7, R. Karabowicz5, N. Katrynska5 ,E. J. Kim11, T. M. Larsen7, J. H. Lee1, Y. K. Lee4,S. Lindahl12, G. Løvhøiden12, Z. Majka5, M. J. Murray11,J. Natowitz8, C.Nygaard7 B. S. Nielsen7, D. Ouerdane7, D.Pal12, F. Rami3, C. Ristea8, O. Ristea11, D. Röhrich9, B. H. Samset12, S. J. Sanders11, R. A. Scheetz1, P. Staszel5, T. S. Tveter12, F. Videbæk1, R. Wada8, H. Yang9, Z. Yin9, I. S. Zgura2 Global Detectors BNL, Bucharest, Strasbourg, John Hopkins, Krakow, NYU, NBI, Kansas, Oslo Michael Murray

  2. What are the dynamics of strange & light quarks? • Baryon number is clearly transported in both rapidity and pT. • Antibaryons and strange quarks are created • How do these different flavors interact • Can we learn something about the initial state of the system from their interaction. From apparatus => data => comparison to NLO QDC => inference concerning flow and limiting fragmentation => thermal descriptions versus rapidity => half finished wild speculation Michael Murray

  3. Broad Range HAdronic Magnetic Spectrometers Global Detectors Michael Murray

  4. Particle Identification TIME-OF-FLIGHT RICH Ring radius vs momentum gives PID  / K separation 25 GeV/c Proton ID up to 35 GeV/c (2 settings) Michael Murray

  5. Invariant yields over a broad range of phase space Michael Murray

  6. Finding  through weak decay to K+,K- Preliminary AuAu y~1 minimum bias, 200GeV N = 12035 Invariant mass of K+K- pair (GeV/c2) Michael Murray

  7. Fitting mT spectra gives dN/dy and T dN/dy = 2.09  1.00 0.25 T = 354  109  35 MeV Consistent with STAR at y=0 Michael Murray

  8. pp => , k, p at 200GeV PRL 98, 252001 =2pT =1/2pT pT (GeV/c) Michael Murray

  9. Baryon transport for pp at s = 62GeV Preliminary Models such as Pythia seriously underestimate the yield of high pT protons at forward rapidities dN/dy =0.7 ey-yb => dN/dx=c dN dy Preliminary Rapidity Michael Murray

  10. AGS dN/dy SPS RHIC 62 “net”proton (BRAHMS preliminary) RHIC 200 LHC 5500 Baryon Transport in AuAu For AuAu collisions a parton my be hit multiple times and the rapidity distribution flattens out Michael Murray

  11. AuAu rapidity loss flattens out between SPS & RHIC y = A -B e-ybeam ybeam Peak of proton dN/dy should fall in acceptance of CASTOR at LHC Michael Murray

  12. Limiting fragmentation pp => , k y-ybeam y-ybeam Michael Murray

  13. Limiting fragmenation even works for p, pbar y-ybeam Michael Murray

  14. Limiting Fragmentation also works in AuAu BRAHMS Preliminary + NA49 1 Npart dN dy y - ybeam Michael Murray

  15. Elliptic flow, v2(pT) is independent of rapidity Preliminary AuAu at √sNN = 200GeV, 0-50% central PRC72 014904 <V2> decreases with y because <pT> decreases with y Michael Murray

  16. V2(pT) scaling at central & forward rapidity Michael Murray

  17. Yields of produced particles are Gaussian Central 62GeV AuAu =>, Kpbar Preliminary dN/dy rapidity Michael Murray

  18. and Are different regions of rapidity in chemical equilibrium? At each rapidity assume chemical equilibrium and strangeness neutrality Michael Murray

  19. Chemical freeze-out BRAHMS PRELIMINARY K-/K+ ratios seem to be controlled by pbar/p Michael Murray

  20. Does pbar/p control rapidity dependence strangeness in pp too? Not so good here Note for pp we have to be careful to conserve quantum numbers in each event Michael Murray

  21. Fit ±, K±, p and pbar dN/dy to a temperature and chemical potentials for strange & light quarks "THERMUS -- A Thermal Model Package for ROOT", S. Wheaton and J. Cleymans, hep-ph/0407174 T=1169 MeV Assumption of strangeness neutrality could be checked by comparing to  yields T=160 MeV T=1483 MeV Michael Murray

  22. Are protons black, white holes?Colour charges are confined If we change the gravitational force with the strong nuclear force then R ~ 1fm. Michael Murray

  23. Black Holes and the uncertainty principle + - Michael Murray

  24. Black Holes radiate with T = 1/(8GM) + Michael Murray

  25. If black holes are charged the temperature changes + - - Temperature - - - - - Charge - Michael Murray

  26. Search for charge white holes @ RHIC Slide 3 M => E Q => B G => 1/2 Michael Murray

  27. First look for white holes in AuAu collisions STAR 200GeV AuAu Michael Murray

  28. First look for white holes in AuAu collisions These points have comparable p-pbar Assuming white hole hypothesis works at 200GeV implies T=1375 MeV for 63GeV, y=0 Michael Murray

  29. Next Steps • Do thermal analysis as a function of centrality • Use particle abundances and average momenta to estimate dET/dy vs √S and centrality. • Test if “White Hole” hypothesis can explain BRAHMS data in terms of thermal distributions Michael Murray

  30. Conclusions • NLO pQCD has trouble describing p and pbar spectra for the forward region of pp collisions • A wide range of phenomena obey limiting fragmentation • Elliptic flow at a given pT is independent of y • Particle yields at a given rapidity can be described within a thermal framework. The temperature falls with √S and y • Somehow we need to explain very rapid, perhaps instant, thermalization of the system with parameters driven by the baryon density. We are investigating the charged “white hole” hypothesis. Michael Murray

  31. Backups Michael Murray

  32. Particle ratios vs rapidity Michael Murray

  33. Acceleration and radiation A stationary observer in the blue region sees the thermal radiation of temperature T = a/2 Mass m 1/a Pictures from Castorina, Kharzeev & Satz hep-ph/0704.1426 Michael Murray

  34. For NA27, the K-/K+ ratio seems to be high NA49 could clarify this Michael Murray

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