Related papers: The QCD rotator with a light quark mass
We present recent results on the critical and pseudo-critical temperatures in (2+1)-flavor QCD with a physical strange quark mass and two degenerate light quark masses extrapolated to the chiral limit and tuned to the physical value,…
A low energy effective field theory model for QCD with a scalar color octet field is discussed. The model relates the gluon mass, the constituent quark masses and the quark condensate. The gluon mass comes about $\sqrt{N_c}\, \Lambda_{QCD}$…
Previous extrapolations of lattice QCD results for the nucleon mass to the physically relevant region of small quark masses, using chiral effective field theory, are extended and expanded in several directions. A detailed error analysis is…
Following the Non-Relativistic QCD approach we use a gauge invariant smearing method with factorization to measure the excitation energies for a heavy $Q\bar{Q}$ system on a $24^3\times 48$ lattice at $\beta=6.2$. The results come from…
We compute the next-to-leading order perturbative QCD corrections to the correlators of nucleon interpolating currents in relativistic nuclear matter. The main new result is the calculation of the O(alpha_s) perturbative corrections to the…
This talks contains a short introduction to Chiral Perturbation Theory and the existing calculations to two-loop order in the mesonic sector. I include a discussion on which quantities the expansion can be organized in. The present best…
We report on the scaling of basic hadronic observables in lattice QCD with N_f=2 maximally twisted Wilson dynamical quarks. We give preliminary results for some of the Gasser-Leutwyler low energy constants, the chiral condensate and the…
We have investigated a closed set of equations for the quark propagator, which has been obtained earlier within a new, nonperturbative approach to two-dimencional covariant gauge QCD. It is shown that this theory implies quark confinement…
We calculate the meson correlators in the $\epsilon$-regime of two-flavor QCD. On a $16^3\times 32$ lattice with $a\sim 0.11$ fm, the lattice simulations are performed with the dynamical overlap fermions. We reduce the sea quark mass down…
The spontaneous breaking of chiral symmetry in QCD is known to be linked to a non-zero density of eigenvalues of the massless Dirac operator near the origin. Numerical studies of two-flavour QCD now suggest that the low quark modes are…
Heavy quark symmetry relations for $B\rightarrow De\bar \nu_e$ and $B\rightarrow D^*e \bar \nu_e$ form factors receive corrections suppressed by powers of the charm quark mass. For small up and down quark massed the leading corrections of…
We use three-flavor chiral perturbation theory ($\chi$PT) to calculate the pressure, light and $s$-quark condensates of QCD in the confined phase at finite temperature to ${\cal O}(p^6)$ in the low-energy expansion. We also include…
The electromagnetic properties of the baryon octet are calculated in quenched QCD on a 20^3 x 40 lattice with a lattice spacing of 0.128 fm using the fat-link irrelevant clover (FLIC) fermion action. FLIC fermions enable simulations to be…
The reasons why a considerable effort is made to resolve the low energy structure of QCD are discussed. The effective field theory used for this purpose is illustrated with the recent progress made in the predictions for pipi scattering and…
We generated configurations with the parametrized fixed-point Dirac operator D_{FP} on a (1.6 fm)^4 box at a lattice spacing a=0.13 fm. We compare the distributions of the three lowest k=1,2,3 eigenvalues in the nu= 0,1,2 topological…
We present the light-flavor quark masses and low energy constants using the 2+1 flavor full-QCD ensembles with stout smeared clover fermion action and Symanzik gauge actions. Both the fermion and gauge actions are tadpole improved…
N flavor QED in two dimensions is reduced to a quantum mechanics problem with N degrees of freedom for which the potential is determined by the ground state of the problem itself. The chiral condensate is determined at all values of…
The low energy structure of the energy momentum tensor in several chiral quark models with SU(3) flavor symmetry is analyzed in the presence of external gravitational fields. To this end a derivative expansion in a curved four dimensional…
In the low energy domain, Chiral Perturbation Theory parametrizes the small chiral symmetry breaking effects, produced by the quark masses $m_u$, $m_d$ and $m_s$, in terms of order parameters of massless QCD. The latter can then, in…
We present the QCD corrections to R_b and to the Delta B=1 effective Hamiltonian in models with a second Higgs field that couples to the quarks respecting the criterion of Minimal Flavor Violation, thus belonging either to the (1,2)_1/2 or…