Universal Formula for Baryon Spectra in Heavy-ion Collisions and its Implications

Abstract

In an unconventional presentation of the data on the transverse momentum spectra of baryons produced in heavy-ion collisions, regularities are found that make possible the discovery of a universal formula valid for $p,\Lambda ,\Xi$ and $\Omega$. The formula describes the baryon distributions over wide ranges of $p_T(0.5{}_{\sim }^{<}{p}_T{}_{\sim }^{<}5$ GeV/c) for $0.06{}_{\sim }^{<}\sqrt{s_{NN}}{}_{\sim }^{<}3$ TeV, except for very peripheral collisions. Some aspects of their empirical properties are derived in the recombination model, resulting in a revelation of some features of the light and strange quark distributions before hadronization. Interpretation of the inverse slopes of their exponential behavior leads to an implication that cannot accommodate the conventional description of fluid flow. This is mainly a study of phenomenology without detailed model input.

Comments: 29 pages, 13 figures