Color randomization of fast gluon-gluon pairs in the quark-gluon plasma

TL;DR

This paper investigates how quickly gluon pairs in the quark-gluon plasma undergo color randomization, finding it to be slow at LHC energies, with implications for baryon production at high transverse momentum.

Contribution

It provides the first detailed analysis of color randomization timescales for gluon pairs in the quark-gluon plasma at LHC conditions, including energy dependence and effects on baryon jet fragmentation.

Findings

Color randomization of gluon pairs is slow at LHC energies.

The average color Casimir deviates from fully randomized values.

Contribution of decuplet states to baryon production diminishes at high pT.

Abstract

We study the color randomization of two-gluon states produced after splitting of a primary fast gluon in the quark-gluon plasma. We find that for the LHC conditions the color randomization of the $gg$ pairs is rather slow. At jet energies $E=100$ and $500$ GeV, for typical jet path length in the plasma in central Pb+Pb collisions, the $SU(3)$-multiplet averaged color Casimir of the $gg$ pair differs considerably from its value $2N_c$ for a fully randomized $gg$ state. Our calculations of the energy dependence for generation of the nearly collinear decuplet $gg$ states, that can lead to the baryon jet fragmentation, show that the contribution of the anomalous decuplet color states to the baryon production should become small at $p_T\gtrsim 10$ GeV.