Abstract
We report on the first lattice calculation of the QCD phase transition using chiral fermions with physical quark masses. This calculation uses quark flavors, spatial volumes between and and temperatures between 139 and 196 MeV. Each temperature is calculated at a single lattice spacing corresponding to a temporal Euclidean extent of . The disconnected chiral susceptibility, shows a pronounced peak whose position and height depend sensitively on the quark mass. We find no metastability near the peak and a peak height which does not change when a 5 fm spatial extent is increased to 10 fm. Each result is strong evidence that the QCD “phase transition” is not first order but a continuous crossover for . The peak location determines a pseudocritical temperature , in agreement with earlier staggered fermion results. However, the peak height is 50% greater than that suggested by previous staggered results. Chiral symmetry is fully restored above 164 MeV, but anomalous symmetry breaking is nonzero above and vanishes as is increased to 196 MeV.
- Received 17 March 2014
DOI:https://doi.org/10.1103/PhysRevLett.113.082001
© 2014 American Physical Society
Viewpoint
Testing a Realistic Quark-Gluon Plasma
Published 18 August 2014
More realistic versions of lattice QCD may lead to a better understanding of how quarks formed hadrons in the early Universe.
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