Centrality dependence of pi^[+/-], K^[+/-], p and p-bar production from sqrt(s_NN)=130 GeV Au + Au collisions at RHIC

TL;DR

Transverse momentum spectra at midrapidity in sqrt[s(NN)] = 130 GeV Au+Au collisions were measured by the PHENIX experiment at RHIC as a function of collision centrality and there is an indication that K(+/-), p, and (-)p yields per participant increase faster than the pi(+/+) yields.

Abstract

Identified pi^[+/-] K^[+/-], p and p-bar transverse momentum spectra at mid-rapidity in sqrt(s_NN)=130 GeV Au-Au collisions were measured by the PHENIX experiment at RHIC as a function of collision centrality. Average transverse momenta increase with the number of participating nucleons in a similar way for all particle species. The multiplicity densities scale faster than the number of participating nucleons. Kaon and nucleon yields per participant increase faster than the pion yields. In central collisions at high transverse momenta (p_T greater than 2 GeV/c), anti-proton and proton yields are comparable to the pion yields.

Figures (3)

• Figure 1: Transverse momentum spectra measured at mid-rapidity for $\pi^{+}, K^{+}, p$ (left) and $\pi^{-}, K^{-}, \overline{p}$ at the three different centrality selections indicated in each panel. The symbols indicated in the top panels apply for all centrality selections.
• Figure 2: Average transverse momentum for $\pi^{+}, K^{+}, p$ (left) and $\pi^{-}, K^{-}, \overline{p}$ as a function of the number of nucleons participating in the collision $N_{part}$. The error bars represent the statistical errors. The systematic errors are discussed in the text. The open points are interpolations from $pp$ and $p\overline{p}$ data, see text for details.
• Figure 3: $dN/dy_{|y=0}$ per participant for $\pi^{+}, K^{+}, p$ (left) and $\pi^{-}, K^{-}, \overline{p}$ as a function of $N_{part}$. The error bars include statistical and systematic errors in $dN/dy$. The dashed lines around the positive hadrons show the effect of the systematic error on $N_{part}$ which affects all curves in the same way.