Energy-Dependent Chemical Potentials of Light Hadrons and Quarks Based on Transverse Momentum Spectra and Yield Ratios of Negative to Positive Particles

Figure 6

Transverse mass and momentum spectra for , , , and at mid-rapidity in central Pb-Pb collisions at (a, d) 12.3, (b, e) 17.3, and (c, f) 2760 GeV. The symbols represent the experimental data reported by the NA49 Collaboration for 12.3 GeV at mid-rapidity [ for [45], () for and [44]], the NA44 Collaboration for 17.3 GeV near mid-rapidity ( for , for , and for and ) [46], and the ALICE Collaboration for 2760 GeV at mid-rapidity [47]. Some data for different particles are divided by suitable factors for clarity. The errors are statistical for 12.3 GeV, are systematic for 17.3 GeV, and are quadratic sum of statistical errors and systematic errors for 2760 GeV. The curves are fits of two-component Erlang function to the spectra.