Cosmic QCD Epoch at Nonvanishing Lepton Asymmetry
Mandy M. Wygas (Fakultät für Physik, Universität Bielefeld, Postfach 100131, 33501 Bielefeld, Germany); Isabel M. Oldengott (Departament de Fisica Teòrica, Universitat de València, 46100 Burjassot, Spain); Dietrich Bödeker (Fakultät für Physik, Universität Bielefeld, Postfach 100131, 33501 Bielefeld, Germany); Dominik J. Schwarz (Fakultät für Physik, Universität Bielefeld, Postfach 100131, 33501 Bielefeld, Germany)
We investigate how a lepton asymmetry impacts the cosmic trajectory in the QCD phase diagram. We study the evolution of chemical potentials during the QCD epoch of the early Universe using susceptibilities from lattice QCD to interpolate between an ideal quark gas and an ideal hadron resonance gas. The lepton asymmetry affects the evolution of all chemical potentials. The standard cosmic trajectory is obtained assuming tiny lepton and baryon asymmetries. For larger lepton asymmetry, the charge chemical potential exceeds the baryon chemical potential before pion annihilation.