A. A. Nikolaev

New approach to canonical partition functions computation in

We propose and test a new approach to computation of canonical partition functions in lattice QCD at finite density. We suggest a few steps procedure. We first compute numerically the quark number density for imaginary chemical potential

N_f=2

i\mu_{qI}

lattice QCD at finite baryon density

. Then we restore the grand canonical partition function for imaginary chemical potential using fitting procedure for the quark number density. Finally we compute the canonical partition functions using high precision numerical Fourier transformation. Additionally we compute the canonical partition functions using known method of the hopping parameter expansion and compare results obtained by two methods in the deconfining as well as in the confining phases. The agreement between two methods indicates the validity of the new method. Our numerical results are obtained in two flavor lattice QCD with clover improved Wilson fermions.

Study of the phase diagram of dense two-color QCD within lattice simulation

In this paper we carry out a low-temperature scan of the phase diagram of dense two-color QCD with

Lattice Study of QCD Phase Structure by Canonical Approach

N_f=2

Novel approach to deriving the canonical generating functional in lattice QCD at a finite chemical potential

quarks. The study is conducted using lattice simulation with rooted staggered quarks. At small chemical potential we observe the hadronic phase, where the theory is in a confining state, chiral symmetry is broken, the baryon density is zero and there is no diquark condensate. At the critical point

Restoring canonical partition functions from imaginary chemical potential

\mu = m_{\pi}/2

Observation of deconfinement in a cold dense quark medium

we observe the expected second order transition to Bose-Einstein condensation of scalar diquarks. In this phase the system is still in confinement in conjunction with non-zero baryon density, but the chiral symmetry is restored in the chiral limit. We have also found that in the first two phases the system is well described by chiral perturbation theory. For larger values of the chemical potential the system turns into another phase, where the relevant degrees of freedom are fermions residing inside the Fermi sphere, and the diquark condensation takes place on the Fermi surface. In this phase the system is still in confinement, chiral symmetry is restored and the system is very similar to the quarkyonic state predicted by SU(

Lattice QCD at finite baryon density using analytic continuation

N_c

Study of lattice QCD at finite baryon density using the canonical approach

) theory at large