Fluctuations, strangeness and quasi-quarks in heavy-ion collisions from lattice QCD

TL;DR

This paper uses lattice QCD to measure susceptibilities related to baryon number, charge, and strangeness, providing predictions for experiments and evidence of quark-like excitations in high-temperature QCD phases.

Contribution

It introduces robust susceptibility ratios as experimental predictions and presents evidence for quark-like quasi-particles in the high-temperature phase of QCD.

Findings

Susceptibility ratios are independent of lattice spacing.

Strangeness production and flavor symmetry breaking are characterized at finite temperature.

Evidence of quark-like excitations in the high-temperature phase of QCD.

Abstract

We report measurements of diagonal susceptibilities for the baryon number, chi_B, electrical charge, chi_Q, third component of isospin, chi_I, strangeness, chi_S, and hypercharge, chi_Y, as well as the off-diagonal chi_BQ, chi_BY, chi_BS, etc. We show that the ratios of susceptibilities in the high temperature phase are robust variables, independent of lattice spacing, and therefore give predictions for experiments. We also investigate strangeness production and flavour symmetry breaking matrix elements at finite temperature. Finally, we present evidence that in the high temperature phase of QCD the different flavour quantum numbers are excited in linkages which are exactly the same as one expects from quarks. We present some investigations of these quark-like quasi particles.