End Point of a First-Order Phase Transition in Many-Flavor Lattice QCD at Finite Temperature and Density

Understand

Towards the feasibility study of the electroweak baryogenesis in realistic technicolor scenario, we investigate the phase structure of (2+Nf)-flavor QCD, where the mass of two flavors is fixed to a small value and the others are heavy.

• For the baryogenesis, an appearance of a first order phase transition at finite temperature is a necessary condition.
• Using a set of configurations of two-flavor lattice QCD and applying the reweighting method, the effective potential defined by the probability distribution function of the plaquette is calculated in the presence of additional many heavy flavors.
• Through the shape of the effective potential, we determine the critical mass of heavy flavors separating the first order and crossover regions and find it to become larger with Nf.