Strangeness Enhancement in Cu+Cu and Au+Au Collisions at \sqrt{s_{NN}} = 200 GeV

TL;DR

This paper presents measurements of strange hadron yields in Cu+Cu and Au+Au collisions at 200 GeV, revealing higher strangeness production in smaller Cu+Cu systems at equal participant numbers, and introduces a parameterization based on multiple collision fractions.

Contribution

It provides new experimental data on strange hadron yields in Cu+Cu and Au+Au collisions and proposes a novel parameterization to describe strangeness enhancement based on multiple collision fractions.

Findings

Strangeness enhancement is higher in Cu+Cu than in Au+Au at the same participant number.

A parameterization based on the fraction of participants with multiple collisions describes the enhancement.

Yields of strange particles increase with the number of participating nucleons.

Abstract

We report new STAR measurements of mid-rapidity yields for the $\Lambda$, $\bar{\Lambda}$, $K^{0}_{S}$, $\Xi^{-}$, $\bar{\Xi}^{+}$, $\Omega^{-}$, $\bar{\Omega}^{+}$ particles in Cu+Cu collisions at \sNN{200}, and mid-rapidity yields for the $\Lambda$, $\bar{\Lambda}$, $K^{0}_{S}$ particles in Au+Au at \sNN{200}. We show that at a given number of participating nucleons, the production of strange hadrons is higher in Cu+Cu collisions than in Au+Au collisions at the same center-of-mass energy. We find that aspects of the enhancement factors for all particles can be described by a parameterization based on the fraction of participants that undergo multiple collisions.