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Nuclear modification factor for identified hadrons at forward rapidity in Au+Au reactions at 200GeV. Radoslaw Karabowicz for the BRAHMS Collaboration Marian Smoluchowski Institute of Physics, Jagiellonian University, Kraków, Poland. Tracking Detectors. Magnets. BRAHMS experiment.
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Nuclear modification factor for identified hadrons at forward rapidity in Au+Au reactions at 200GeV Radoslaw Karabowicz for the BRAHMS Collaboration Marian Smoluchowski Institute of Physics, Jagiellonian University, Kraków, Poland
Tracking Detectors Magnets BRAHMS experiment Data analyzed: Au+Au, p+p at sqrt(s_NN)=200GeV 2
RICH Pid m2 [GeV2/c4] r [cm] RICH Pid – 3 sigma cut. In the overlapping regions Pid based on statistical weighting of Gaussian distibution in r. p [GeV/c] 3
y-pT map coverage Different colors – different angle and field settings • trigger normalization • acceptance • tracking efficiency • Pid efficiency Au+Au 200 AGeV pions 4
RCP in Au+Au @ 200 AGeV [(d2NAu+Au/dpTdy)/<Ncoll>]0-10% RCP= [(d2NAu+Au/dpTdy)/<Ncoll>]40-50% 6
RAA in Au+Au @ 200 AGeV 1 d2NAu+Au/dpTdy RAA= <Ncoll> d2Nppinel/dpTdy 6 7 Increase of ratios with decreasing centrality Pions and kaons ratios flat Protons show Cronin peak at pt=2
RAA comparison with RCP RCP and RAA are consistent for pions and kaons For protons RCP shows suppression, while RAA shows enhancement 8
RAA at y=0 and y=3.1 RAA for pions at forward rapidities agrees with RAA at midrapidity 9
RCP at y=0 and y=3.1 RCP for pions at forward rapidities copies the behaviour of RCP at midrapidity 10
RCP at y=0 and y=3.0 For protons however data at forward rapidity show significant suppression in RCP 11
SUMMARY • identified particle yields has been measured by BRAHMS at forward rapidity for Au+Au and p+p collisions • RAA shows significant suppression for pions and kaons, but for protons it shows enhancement • RCP and RAA are consistent for pions and kaons, but deviate for protons • no difference in pion RAA between midrapidity (PHENIX p0) and forward rapidity (BRAHMS p++p-/2) consistent with surface jet-emission • baryons’ RCP shows suppression at forward rapidities in contrast with midrapidity • pions RAA shows stronger suppression as compared to RdAu 13
The BRAHMS Collaboration I.Arsene11, I.G. Bearden6, D. Beavis1, S.Bekele10, C. Besliu9, B. Budick5, H. Bøggild6 , C. Chasman1, C. H. Christensen6, P. Christiansen6, R.Clarke9, R.Debbe1, J. J. Gaardhøje6, K. Hagel7, H. Ito1, A. Jipa9, J. I. Jordre9, F. Jundt2, E.B.Johnson10, J.I.Jordre8, C.Jørgensen6, R. Karabowicz3, E. J. Kim10, T.M.Larsen6, J. H. Lee1, Y. K.Lee4, S.Lindal11, G. Løvhøjden2, Z. Majka3, M. Murray10, J. Natowitz7, B.S.Nielsen6, D.Ouerdane6, R.Planeta3, F. Rami2, C.Ristea6, O.Ristea9, D. Röhrich8, B. H. Samset11, S. J. Sanders10, R.A.Sheetz1, P. Staszel3, T.S. Tveter11, F.Videbæk1, R. Wada7, H.Yang8, Z. Yin8,and I. S. Zgura9 1Brookhaven National Laboratory, USA, 2IReS and Université Louis Pasteur, Strasbourg, France 3Jagiellonian University, Cracow, Poland, 4Johns Hopkins University, Baltimore, USA, 5New York University, USA 6Niels Bohr Institute, University of Copenhagen, Denmark 7Texas A&M University, College Station. USA, 8University of Bergen, Norway 9University of Bucharest, Romania,10University of Kansas, Lawrence,USA 11 University of Oslo Norway 48 physicists from 11 institutions 14