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Michael Murray1 Global Detectors 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, J. J. Gaardh ø je 7, K. Hagel 8, H. Ito 1, A. Jipa 10, E.B.Johnson 11, J. I. J ø rdre 9, C. E. J ø rgensen 7, R. Karabowicz 5, N. Katrynska 5,E. J. Kim 11, T. M. Larsen 7, J. H. Lee 1, Y. K. Lee 4,S. Lindahl 12, G. L ø vh ø iden 12, Z. Majka 5, M. J. Murray 11,J. Natowitz 8, C.Nygaard 7 B. S. Nielsen 7, D. Ouerdane 7, D.Pal 12, F. Rami 3, C. Ristea 8, O. Ristea 11, D. R ö hrich 9, B. H. Samset 12, S. J. Sanders 11, R. A. Scheetz 1, P. Staszel 5, T. S. Tveter 12, F. Videb æ k 1, R. Wada 8, H. Yang 9, Z. Yin 9, I. S. Zgura 2 BNL, Bucharest, Strasbourg, John Hopkins, Krakow, NYU, NBI, Kansas, Oslo

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Michael Murray2 What are the dynamics of strange & light quarks? Baryon number is clearly transported in both rapidity and p T. 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

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Michael Murray3 Global Detectors Broad Range HAdronic Magnetic Spectrometers

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Michael Murray4 TIME-OF-FLIGHT 0< <1 (MRS) 1.5< <4 (FS) p max (2 cut) TOFW (GeV/c) TOFW2 (GeV/c) TOF1 (GeV/c) TOF2 (GeV/c) K/ K/p Ring radius vs momentum gives PID / K separation 25 GeV/c Proton ID up to 35 GeV/c (2 settings) RICH Particle Identification

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Michael Murray5 Invariant yields over a broad range of phase space

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Michael Murray6 N = 120 35 Finding through weak decay to K +,K - Invariant mass of K + K - pair (GeV/c 2 ) Preliminary AuAu y~1 minimum bias, 200GeV

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Michael Murray7 dN/dy = 2.09 1.00 0.25 T = 354 109 35 MeV Consistent with STAR at y=0 Fitting m T spectra gives dN/dy and T

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Michael Murray8 pp => , k, p at 200GeV p T (GeV/c) PRL 98, =2p T =1/2p T

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Michael Murray9 Baryon transport for pp at s = 62GeV dN/dy =0.7 e y-yb => dN/dx=c Rapidity dN dy Models such as Pythia seriously underestimate the yield of high p T protons at forward rapidities Preliminary

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Michael Murray10 Baryon Transport in AuAu “net”proton AGS SPS RHIC 62 RHIC 200 LHC 5500 dN/dy (BRAHMS preliminary) For AuAu collisions a parton my be hit multiple times and the rapidity distribution flattens out

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Michael Murray11 y = A -B e -ybeam AuAu rapidity loss flattens out between SPS & RHIC ybeam Peak of proton dN/dy should fall in acceptance of CASTOR at LHC

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Michael Murray12 Limiting fragmentation pp => , k y-ybeam

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Michael Murray13 Limiting fragmenation even works for p, pbar y-ybeam

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Michael Murray14 Limiting Fragmentation also works in AuAu BRAHMS Preliminary + NA49 dN dy 1 N part y - ybeam

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Michael Murray15 PRC Preliminary AuAu at √s NN = 200GeV, 0-50% central Elliptic flow, v 2 (p T ) is independent of rapidity decreases with y because decreases with y

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Michael Murray16 V 2 (p T ) scaling at central & forward rapidity

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Michael Murray17 Yields of produced particles are Gaussian Central 62GeV AuAu => , K pbar Preliminary rapidity dN/dy

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Michael Murray18 At each rapidity assume chemical equilibrium and strangeness neutrality and Are different regions of rapidity in chemical equilibrium?

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Michael Murray19 Chemical freeze-out BRAHMS PRELIMINARY K - /K + ratios seem to be controlled by pbar/p

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Michael Murray20 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

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Michael Murray21 Fit ±, K ±, p and pbar dN/dy to a temperature and chemical potentials for strange & light quarks T=116 9 MeV T=148 3 MeV T=160 MeV "THERMUS -- A Thermal Model Package for ROOT", S. Wheaton and J. Cleymans, hep-ph/ Assumption of strangeness neutrality could be checked by comparing to yields

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Michael Murray22 Are protons black, white holes? Colour charges are confined If we change the gravitational force with the strong nuclear force then R ~ 1fm.

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Michael Murray23 Black Holes and the uncertainty principle + -

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Michael Murray24 Black Holes radiate with T = 1/(8 GM) +

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Michael Murray25 If black holes are charged the temperature changes Temperature Charge

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Michael Murray26 Slide 3 Search for charge white RHIC M => E Q => B G => 1/2

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Michael Murray27 First look for white holes in AuAu collisions STAR 200GeV AuAu

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Michael Murray28 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

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Michael Murray29 Next Steps Do thermal analysis as a function of centrality Use particle abundances and average momenta to estimate dE T /dy vs √S and centrality. Test if “White Hole” hypothesis can explain BRAHMS data in terms of thermal distributions

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Michael Murray30 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 p T 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.

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Michael Murray31 Backups

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Michael Murray32 Particle ratios vs rapidity

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Michael Murray33 Acceleration and radiation A stationary observer in the blue region sees the thermal radiation of temperature T = a/2 Pictures from Castorina, Kharzeev & Satz hep-ph/ Mass m 1/a

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Michael Murray34 For NA27, the K - /K + ratio seems to be high NA49 could clarify this

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