G. Schierholz

Baryonic flux in quenched and two-flavor dynamical QCD after Abelian projection

We study the distribution of color electric flux of the three-quark system in quenched and full QCD (with N{sub f}=2 flavors of dynamical quarks) at zero and finite temperature. To reduce ultraviolet fluctuations, the calculations are done in the Abelian projected theory fixed to the maximally Abelian gauge. In the confined phase we find clear evidence for a Y-shape flux tube surrounded and formed by the solenoidal monopole current, in accordance with the dual superconductor picture of confinement. In the deconfined, high temperature phase monopoles cease to condense, and the distribution of the color electric field becomes Coulomb-like.

On the dynamics of color magnetic monopoles in full QCD

Abstract We present first results on the dynamics of monopoles in full QCD with N f = 2 flavors of dynamical quarks. Among the quantities being studied are the monopole density and the monopole screening length, the static potential as well as the profile of the color electric flux tube. Furthermore, we derive the low-energy effective monopole action.

Dynamics of monopoles and flux tubes in two-flavor dynamical QCD

We investigate the confining properties of the QCD vacuum with N{sub f}=2 flavors of dynamical quarks, and compare the results with the properties of the quenched theory. We use nonperturbatively O(a) improved Wilson fermions to keep cutoff effects small. We focus on color magnetic monopoles. Among the quantities we study are the monopole density and the monopole screening length, the static potential and the profile of the color electric flux tube. We furthermore derive the low-energy effective monopole action. Marked differences between the quenched and dynamical vacuum are found.

Finite temperature phase transition in lattice QCD with Nf = 2 nonperturbatively improved Wilson fermions at Nt = 8

Abstract The finite temperature lattice QCD with Nf = 2 nonperturbatively improved Wilson fermions is studied on 1638 lattice. Using abelian projection after fixing to MA gauge we determine the transition temperature for mπ/mϱ ∼ 0.8.

Profiles of a Broken String in Two-Flavor QCD below and above the Finite Temperature Transition

We study the Abelian flux tube profile of the mesonic and baryonic configurations formed by static quarks below and above the finite-temperature transition in Nf = 2 lattice QCD. To reduce the effects of ultra-violet fluctuations, we measure Abelian distributions of the action density, the color-electric field and the monopole current in the maximally Abelian projection. For fixed temperature, T (with T/ Tc < 1), we observe a clear signal of the string breaking for a large test quark separation R. The electric field becomes Coulomb-like and the circulating monopole current disappears. We also study the temperature dependence of the flux profile for fixed R ≈ 0.7 fm. The squeezed flux disappears above Tc.

Heavy quark potential in lattice QCD at finite temperature

Results of the study of lattice QCD with two flavors of nonperturbatively improved Wilson fermions at finite temperature are presented. The transition temperature for m_{pi}/m_{rho} sim 0.8 and lattice spacing a sim 0.12 fm is determined. A two-exponent ansatz is successfully applied to describe the heavy quark potential in the confinement phase.

The profile of the broken string in the confined and deconfined phase in full QCD

Abstract We study the profile of the broken string (flux tube) in the maximally abelian gauge below and above the finite temperature phase transition in full QCD. In the deconfinement phase, the flux tube disappears and the electric field apperas to be Coulomb-like. In the confinement phase, but near T., at shorter distances a flux tube is formed like at zero temperature, while at larger distances the tube disappears similar to the deconfinement phase.

Finite temperature QCD with two flavors of dynamical quarks on 243 × 10 lattice

We present results obtained in QCD with two flavors of non‐perturbatively improved Wilson fermions at finite temperature on 163 × 8 and 243 × 10 lattices. We determine the transition temperature in the range of quark masses 0.6 < mπ/mρ < 0.8 at lattice spacing a≈0.1 fm and extrapolate the transition temperature to the continuum and to the chiral limits.

Structure of the baryonic flux tube in Nf = 2 lattice QCD at finite temperature

Abstract We study the flux tube profile in the baryonic system in full QCD at finite temperature on N t = 8 lattice. We fix the maximally Abelian gauge and measure the monopole and the photon parts of the Abelian action density, the color electric field and the monopole current on both sides of the finite temperature transition. We demonstrate the disappearance of the flux tube in the high temperature phase.