Antiparticle to particle ratios and identified hadron spectra in Cu plus Cu and Au plus Au collisions

作者：Veres Gabor I^*

来源：Journal of Physics G: Nuclear and Particle Physics , 2007, 34(8): S1103-S1107.

DOI：10.1088/0954-3899/34/8/S165

New results on antiparticle to particle ratios in Cu+Cu and Au+Au collisions at root(NN)-N-S = 62.4 and 200 GeV from the PHOBOS experiment at RHIC are presented. Transverse momentum spectra of pions, kaons, protons and antiprotons from Au+Au collisions at root(NN)-N-S = 62.4 GeV close to mid-rapidity are also discussed. Antiparticle to particle ratios are found to be remarkably independent of the collision centrality in both colliding systems. The collision energy dependence of the (p) over bar /p ratios is very significant in Cu+Cu collisions. Baryons are found to have substantially harder transverse momentum spectra than mesons. The p(T) region in which the proton to pion ratio reaches unity in central Au+Au collisions at root(NN)-N-S = 62.4 GeV fits into a smooth trend as a function of collision energy. The observed particle yields at very low p(T) are comparable to extrapolations from higher p(T) for kaons, protons and antiprotons. The net proton yield at mid-rapidity is found to be proportional to the number of participant nucleons in Au+Au collisions at 62.4 and 200 GeV energies.

• 出版日期2007-8