Dr Pawel Staszel (Jagiellonian University)
The BRAHMS results on the proton-to-pion ratio pT-dependence in the RHIC range of baryo-chemical potential N. Katryńska, Z. Majka (for the BRAHMS Collaboration) BRAHMS measurement of proton-to-pion ratios in Au+Au and p+p at (s NN) ½ = 62.4 GeV and 200 GeV will be presented as a function of transverse momentum and collision centrality within the pseudorapidity range 0 < η < 3. The baryo-chemical potential, μB, for the indicated data spans from μB ~ 25 MeV ( (s NN) ½ = 200 GeV, η = 0) to μB ~ 260 MeV ((s NN) ½ = 62.4 GeV, η ~ 3) . A striking agreement between p/π(p T) ratio measured for Au+Au collisions at (s NN) ½ = 200 GeV (η ~ 2.2) and at (s NN) ½ = 62.4 GeV (η ~ 0) is observed, where the properties of the bulk medium can be described with the common value of μB = 65 MeV. The p/π ratio for Au+Au system at (s NN) ½ = 62.4 GeV, η ~ 3 reaches astounding value of 8-10 at pT = 1.5 GeV/c. For these energy and pseudorapidity interval no centrality dependency of p/π ratio is observed. Comparison of the measured p/π+ and pbar/π- ratios at different beam energies and rapidities with theoretical models [2,3,4] will be provided.  I. Arsene, Quark Matter Conference 2006, Shanghai, China, November 14-22, 2006.  R. C. Hwa and C. B. Yang, Phys.Rev. C 78, (2008) 024907.  W. Broniowski, B. Biedroń, Phys. Rev. C 75, (2007) 054905.  Lin, Zi-Wei, Phys. Rev. C 72, (2005) 064901.
Natalia Katryńska (Institute of Physics Jagiellonian University)
Prof. Zbigniew Majka (Institute of Physics Jagiellonian University)