TY - JOUR
T1 - Rapidity dependence of the proton-to-pion ratio in Au plus Au and p plus p collisions at vs-NN=62.4 and 200 GeV
AU - Arsene...[et al.], I.G.
AU - Bearden, Ian
AU - Bøggild, Hans
AU - Christensen, Christian Holm
AU - Dalsgaard, Hans Hjersing
AU - Gaardhøje, Jens Jørgen
AU - Larsen, Truls Martin
AU - Nygaard, Casper
AU - Nielsen, Børge Svane
PY - 2010/2/1
Y1 - 2010/2/1
N2 - The proton-to-pion ratios measured in the BRAHMS experiment for Au + Au and p + p collisions at sqrt(sN N) = 62.4 and 200 GeV are presented as a function of transverse momentum and collision centrality at selected pseudorapidities in the range of 0-3.8. A strong pseudorapidity dependence of these ratios is observed. We also compare the magnitude and pT-dependence of the p / π+ ratios measured in Au + Au collisions at sqrt(sN N) = 200 GeV and η ≈ 2.2 with the same ratio measured at sqrt(sN N) = 62.4 GeV and η = 0. The great similarity found between these ratios throughout the whole pT range (up to 2.2 GeV / c) is consistent with particle ratios in A + A collisions being described with grand-canonical distributions characterized by the baryo-chemical potential μB. At the collision energy of 62.4 GeV, we have observed a unique point in pseudorapidity, η = 3.2, where the p / π+ ratio is independent of the collision system size in a wide pT-range of 0.3 ≤ pT ≤ 1.8 GeV / c.
AB - The proton-to-pion ratios measured in the BRAHMS experiment for Au + Au and p + p collisions at sqrt(sN N) = 62.4 and 200 GeV are presented as a function of transverse momentum and collision centrality at selected pseudorapidities in the range of 0-3.8. A strong pseudorapidity dependence of these ratios is observed. We also compare the magnitude and pT-dependence of the p / π+ ratios measured in Au + Au collisions at sqrt(sN N) = 200 GeV and η ≈ 2.2 with the same ratio measured at sqrt(sN N) = 62.4 GeV and η = 0. The great similarity found between these ratios throughout the whole pT range (up to 2.2 GeV / c) is consistent with particle ratios in A + A collisions being described with grand-canonical distributions characterized by the baryo-chemical potential μB. At the collision energy of 62.4 GeV, we have observed a unique point in pseudorapidity, η = 3.2, where the p / π+ ratio is independent of the collision system size in a wide pT-range of 0.3 ≤ pT ≤ 1.8 GeV / c.
U2 - 10.1016/j.physletb.2009.12.055
DO - 10.1016/j.physletb.2009.12.055
M3 - Journal article
SN - 0370-2693
VL - 684
SP - 22
EP - 27
JO - Physics Letters B
JF - Physics Letters B
IS - 1
ER -