Parton Distributions at Hadronization from Bulk Dense Matter Produced at RHIC

TL;DR

This paper analyzes hadron spectra from heavy-ion collisions at RHIC to infer the properties of constituent quark distributions at hadronization, supporting quark coalescence models and revealing insights into partonic matter.

Contribution

It provides evidence for effective constituent quark distributions at hadronization and demonstrates the success of the AMPT model in reproducing experimental spectra.

Findings

Stronger transverse momentum distribution for strange quarks.

Consistent quark ratios across different hadron spectra.

AMPT model accurately reproduces hyperon and phi meson spectra.

Abstract

We present an analysis of $\Omega$, $\Xi$, $\Lambda$ and $\phi$ spectra from Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV in terms of distributions of effective constituent quarks at hadronization. Consistency in quark ratios derived from various hadron spectra provides clear evidence for hadron formation dynamics as suggested by quark coalescence or recombination models. We argue that the constituent quark distribution reflects properties of the effective partonic degrees of freedom at hadronization. Experimental data indicate that strange quarks have a transverse momentum distribution flatter than that of up/down quarks consistent with hydrodynamic expansion in partonic phase prior to hadronization. After the AMPT model is tuned to reproduce the strange and up/down quark distributions, the model can describe the measured spectra of hyperons and $\phi$ mesons very well where hadrons are formed through dynamical coalescence.