Related papers: Extended QCD(2) from dimensional projection of QCD…
We investigate quantum chromodynamics with two colors at nonvanishing density using Dyson-Schwinger equations. Lattice methods do not have a complex action problem in this theory. Thus, we can benchmark our results and the effect of…
Explicit quark-hadron duality in the limit of heavy quark mass is studied using the 't Hooft model, where both partonic and hadronic amplitudes may be computed exactly. Results for weak decays of heavy mesons are presented for both standard…
We investigate the low-temperature phase of QCD and the crossover region with two light flavors of quarks. The chiral expansion around the point $(T,m=0)$ in the temperature vs. quark-mass plane indicates that a sharp real-time excitation…
Macroscopic properties of the strong interaction near its chiral phase transition exhibit scaling behaviors, which are the same as those observed close to the magnetic transition in a 3-dimensional classical spin system with $O(4)$…
In this paper we numerically demonstrate that massless two-dimensional QCD is not integrable. To this aim, we explicitly solve the 't Hooft integral equation for bound states by an adaptive spline procedure, and compute the decay…
We formulate a dressed perturbative expansion of QCD, where the standard diagrams are evaluated in the presence of a constant external gluon field whose magnitude is gaussian distributed. The approach is Poincar{\'e} and gauge invariant,…
We study the scaling behavior of the two-flavor chiral phase transition using an effective quark-meson model. We investigate the transition between infinite-volume and finite-volume scaling behavior when the system is placed in a finite…
We simulate lattice QCD with 2 flavours of massless quarks on lattices of temporal extent N_t=8, to study the finite temperature transition from hadronic matter to a quark-gluon plasma. A modified action which incorporates an irrelevant…
The two-flavor quark-meson model is used as a low-energy effective model for QCD to study inhomogeneous chiral condensates at finite quark chemical potential $\mu$ in a constant magnetic background $B$. We determine the parameters of the…
We employ a nonrelativistic version of QCD (NRQCD) to study heavy quark-antiquark bound states in the lowest approximation without fine structure. We use gluon configurations on a 16^3 by 48 lattice at beta=6.2 from the UKQCD collaboration.…
Analytical functions for the propagators of QCD, including a set of chiral quarks, are derived by a one-loop massive expansion in the Landau gauge, deep in the infrared. By analytic continuation, the spectral functions are studied in…
We studied meson-meson interactions using the 't Hooft model, which represents QCD in 1+1 dimensions and assumes a large number of colors ($N_c$). The dominant interactions in this large $N_c$ limit are generated by quark exchange. Our…
Within a linear sigma model framework, possible mixing between two chiral nonets (a two quark nonet, and a four quark nonet) below 2 GeV is studied. Incorporating the U(1)$_A$ behavior of the underlying QCD, and working in the isospin…
The recent progress on unquenched QCD simulations is critically reviewed. After some discussions on problems and subtleties in unquenched simulations, hadron spectra obtained from both quenched and unquenched simulations are compared among…
We explore corrections to the "hard wall" gravity dual of QCD with two-form tensor fields. These fields correspond to a dimension three quark bilinear in QCD, which generates states with 1(--) and 1(+-) quantum numbers, or omega/rho-like…
We use general arguments to show that coloured QCD states when restricted to gauge invariant local observables are mixed. This result has important implications for confinement: a pure colourless state can never evolve into two coloured…
The temperature dependence of quark and gluon condensates in QCD as precursor of the chiral and deconfining phase transition is modelled with a conformally extended non-linear sigma-model including broken chiral and scale invariance. The…
The exact nature of the QCD phase transition has still not been determined conclusively, and there are contradictory results from lattice QCD simulations about the scaling behavior for two quark flavors. Ultimately, this issue can be…
We consider the two- and three-flavor QMD models as renormalizable low-energy models for QCD at finite quark chemical potentials with quarks, mesons, and diquarks as effective degrees of freedom. Using the on-shell scheme the parameters in…
Using DLCQ as a nonperturbative method, we test Fock-space truncations in ${\rm QCD}_{1+1}$ by studying the mass spectra of hadrons in colour SU(2) and SU(3) at finite harmonic resolution $K$. We include $q\bar q q\bar q$ states for mesons…