Resonances Do Not Equilibrate

Abstract

We discuss, in qualitative and quantitative fashion, the yields of hadron resonances. We show that these yields, in general, are not in chemical equilibrium. We evaluate the non-equilibrium abundances in a dynamic model implementing the $1+2\leftrightarrow 3$ resonance formation reactions. Due to the strength of these reactions, we show the $\Sigma (1385)$ enhancement, and the $\Lambda (1520)$ suppression explicitly.

Comments: 12 pages, in Fourth Workshop on Particle Correlations and Femtoscopy (WPCF2008), Krakow, September 11-14, 2008