Nuclear stopping and rapidity loss in Au+Au collisions at sqrt{s_{NN}}=62.4 GeV

TL;DR

This paper measures proton and anti-proton spectra in gold-gold collisions at 62.4 GeV, analyzing baryon transport and rapidity loss to understand baryon stopping in high-energy nuclear collisions.

Contribution

It provides detailed rapidity distributions of protons and anti-protons over a wide range, and quantifies rapidity loss, comparing results to theoretical models.

Findings

Net-proton yield is roughly constant near mid-rapidity and increases at higher rapidities.

Mean rapidity loss is approximately 2 units from beam rapidity.

Results are compared with model predictions and systematics across energies.

Abstract

Transverse momentum spectra of protons and anti-protons measured in the rapidity range 0<y<3.1 from 0-10% central Au+Au collisions at sqrt{s_{NN}}=62.4 GeV are presented. The rapidity densities, dN/dy, of protons, anti-protons and net-protons N()p-N(pbar) have been deduced from the spectra over a rapidity range wide enough to observe the expected maximum net-baryon density. From mid-rapidity to y=1 the net-proton yield is roughly constant (dN/dy ~ 10),but rises to dN/dy ~25 at 2.3<y<3.1. The mean rapidity loss is 2.01 +-0.16 units from beam rapidity. The measured rapidity distributions are compared to model predictions. Systematics of net-baryon distributions and rapidity loss vs. collision energy are discussed.