Lepton asymmetry and the cosmic QCD transition
Abstract
We study the influence of lepton asymmetries on the evolution of the early Universe. The lepton asymmetry l is poorly constrained by observations and might be orders of magnitudes larger than the observed baryon asymmetry b simeq 10-10, |l|/b <= 2 × 108. We find that lepton asymmetries that are large compared to the tiny baryon asymmetry, can influence the dynamics of the QCD phase transition significantly. The cosmic trajectory in the μB-T phase diagram of strongly interacting matter becomes a function of lepton (flavour) asymmetry. For tiny or vanishing baryon and lepton asymmetries lattice QCD simulations show that the cosmic QCD transition is a rapid crossover. However, for large lepton asymmetry, the order of the cosmic transition remains unknown.
- Publication:
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Journal of Cosmology and Astroparticle Physics
- Pub Date:
- November 2009
- DOI:
- arXiv:
- arXiv:0906.3434
- Bibcode:
- 2009JCAP...11..025S
- Keywords:
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- High Energy Physics - Phenomenology;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- 23 pages, 14 figures