Finite density phase transition of QCD with $N_f=4$ and $N_f=2$ using canonical ensemble method

Understand

In a progress toward searching for the QCD critical point, we study the finite density phase transition of $N_f = 4$ and 2 lattice QCD at finite temperature with the canonical ensemble approach.

• We develop a winding number expansion method to accurately project out the particle number from the fermion determinant which greatly extends the applicable range of baryon number sectors to make the study feasible.
• Our lattice simulation was carried out with the clover fermions and improved gauge action.
• For a given temperature, we calculate the baryon chemical potential from the canonical approach to look for the mixed phase as a signal for the first order phase transition.