Signals of quark combination at hadronization in $pp$ collisions at $\sqrt{s}=200$ GeV

Abstract

We find signals of quark combination at hadronization from the experimental data of pT spectra of hadrons at mid-rapidity in pp collisions at √ s = 200 GeV. The first is the constituent quark number scaling property for pT spectra of Ω − and φ and that for pT spectra of p and ρ 0 . The second is that pT spectra of Λ, Ξ − , and K * 0 can be self-consistently described using the spectrum of strange quarks from φ data and that of up/down quarks from p data in the equal-velocity combination mechanism. The third is that experimental data for pT spectrum of D * + are also well described using the spectrum of up/down quarks from p data and that of charm quarks from perturbative QCD calculations. These results indicate a similarity between hadron production in pp collisions at √ s = 200 GeV and that at LHC energies. We predict pT spectra of single-charm hadrons and their spectrum ratios. We suggest systematic measurements in pp collisions at √ s = 200 GeV in future so as to better understand the property of small parton system created in pp collisions at different collision energies.