2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/187406With the experimental data from STAR and PHENIX on the centrality dependence of the $p_T$ spectra of protons and anti-protons produced at mid-rapidity in Au+Au collisions at 200 GeV, we show that for protons and anti-protons there exists a scaling distribution independent of the colliding centrality. The scaling functions can also describe data from BRAHMS for both proton and anti-proton spectra at $y=2.2$ and 3.2. The scaling behaviors are shown to be incompatible with the usual string fragmentation scenario for particle production.5 pages in revtex,7 eps figures included, will be appeared in Phys. Rev. CNuclear Theorytext