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We study the transverse and longitudinal gluon propagators in the Landau-gauge lattice QCD with gauge group $SU(2)$ at nonzero quark chemical potential and zero temperature. We show that both propagators demonstrate substantial dependence on the quark chemical potential. This observation contradicts to earlier findings by other groups., Comment: 11 pages, 4 fugures, talk presented at the 2nd International Workshop on Theory of Hadronic Matter Under Extreme Conditions (Dubna, 16-19 September 2019) by Roman Rogalyov

The properties of the thermal Abelian color-magnetic monopoles in the maximally Abelian gauge are studied in the vicinity of the confinement-deconfinement phase transition in the lattice $SU(3)$ gluodynamics and lattice QCD. We compute the density and interaction parameters of the thermal monopoles. We find that the density of the thermal monopoles $\rho(T)$ jumps up near the transition temperature $T_c$. Additionally we present new results on the percolation transition in $SU(3)$ gluodynamics which is known to coincide in gluodynamics with the confinement-deconfinement phase transition., Comment: 7 pages, 6 figures, presented at the 31st International Symposium on Lattice Field Theory, July 29 - August 3 2013, Mainz, Germany

We study the deconfinement transition in two-flavour lattice QCD with dynamical overlap fermions. Our simulations have been carried out on a $16^3 \times 6$ lattice at a pion mass around 500 MeV with a special HMC algorithm without any approximation such as fixed topology. We consider several temperatures from 220 MeV which is close to the deconfinement to 280 MeV which is above it. The dependence of the Polyakov loop, the chiral condensate, the Dirac spectra and the connected part of chiral susceptibility on the inverse gauge coupling has been studied. Our data indicates that the transition point lies between $\beta = 7.6$ and $\beta = 8.1$, but a more precise determination is not possible with our present statistics., Comment: refs. added

QCD lattice simulations with 2+1 flavours typically start at rather large up-down and strange quark masses and extrapolate first the strange quark mass to its physical value and then the up-down quark mass. An alternative method of tuning the quark masses is discussed here in which the singlet quark mass is kept fixed, which ensures that the kaon always has mass less than the physical kaon mass. Using group theory the possible quark mass polynomials for a Taylor expansion about the flavour symmetric line are found, which enables highly constrained fits to be used in the extrapolation of hadrons to the physical pion mass. Numerical results confirm the usefulness of this expansion and an extrapolation to the physical pion mass gives hadron mass values to within a few percent of their experimental values., 14 pages, 11 figures. Contribution to Lattice2010, Villasimius, Italy

The SU(2) gluon propagator in Landau gauge is studied on the lattice. Our gauge fixing procedure employs simulated annealing and Z(2)-flips. It finds higher maxima of the gauge functional compared with those obtained with the standard overrelaxation and leads to systematic deviations of the gluon propagator in the infrared region. In particular, finite-size effects for lattice sizes from (1.7 fm)^4 up to (6.5 fm)^4 become weak. The propagator shows a plateau at p \approx 300 MeV., Comment: 7 pages, 4 figures, poster presented at Lattice 2007, Regensburg

We present results of finite temperature QCD from N_f=2 flavors of non-perturbatively improved Wilson fermions on lattices with N_t=8, 10 and 12. The transition temperature T_c is determined for the first time at lattice spacings as low as a = 0.08 fm, albeit at pion masses 1.3 < r_0 m_��. We furthermore compute the screening masses in various color channels at T>T_c., 7 pages, 3 figures, contribution to Lattice 2007, Regensburg, Germany, 30 July - 4 August 2007

QCD results are presented for a 2+1 flavour fermion clover action (which we call the SLiNC action). A method of tuning the quark masses to their physical values is discussed. In this method the singlet quark mass is kept fixed, which solves the problem of different renormalisations (for singlet and non-singlet quark masses) occuring for non-chirally invariant lattice fermions. This procedure enables a wide range of quark masses to be probed, including the case with a heavy up-down quark mass and light strange quark mass. Preliminary results show the correct splittings for the baryon (octet and) decuplet spectrum., 7 pages; talk given at the XXVII International Symposium on Lattice Field Theory, July 26-31 2009, Peking University, Beijing, China

We study SU(2) gluodynamics at finite temperature near the deconfining phase transition. We create the lattice ensembles using the tadpole improved Luscher-Weisz action. The overlap Dirac operator is used to determine the following three aspects of vacuum structure: (i) The topological susceptibility is evaluated at various temperatures across the phase transition, (ii) the overlap fermion spectral density is determined and found to depend on the Polyakov loop above the phase transition and (iii) the corresponding localization properties of low lying eigenmodes are investigated., Comment: 7 pages, 11 figures, presented at the XXV International Symposium on Lattice Field Theory, July 30 - August 4 2007, Regensburg