相关论文: Flavor symmetry breaking in mixed-action QCD
We study the phase structure of mixed-action QCD with two Wilson sea quarks and any number of chiral valence quarks (and ghosts), starting from the chiral lagrangian. A priori, the effective theory allows for a rich phase structure,…
We discuss simulations with different lattice Dirac operators for sea and valence quarks. A goal of such a "mixed" action approach is to probe deeper the chiral regime of QCD by enabling simulations with light valence quarks. This is…
We report on our simulations with Neuberger valence fermions on CLS $N_f=2$ configurations with non-perturbatively $O(a)$-improved Wilson sea quarks. We consider the matching of QCD to ChPT in the so called mixed-regime in which the sea…
We report on our first experiences with a mixed action setup with overlap valence quarks and non-perturbatively O(a) improved Wilson sea quarks. For the latter we employ CLS Nf=2 configurations with light sea quark masses at small lattice…
We discuss a mixed-action approach in which sea quarks are regularised using non-perturbatively ${\rm O}(a)$ improved Wilson fermions, while a fully-twisted tmQCD action is used for valence quarks. In this setup, automatic ${\rm O}(a)$…
We present further analyses of the finite-temperature phase structure of lattice QCD with the Wilson quark action based on spontaneous breakdown of parity-flavor symmetry. Results are reported on (i) an explicit demonstration of spontaneous…
We study lattice QCD with staggered sea and Ginsparg-Wilson valence quarks. The Symanzik effective action for this mixed lattice theory, including the lattice spacing contributions of O(a^2), is derived. Using this effective theory we…
We investigate the phase diagram of QCD at small chemical potentials, ie, when chiral and flavour symmetry breaking involves the pairing of a quark and an antiquark. The phase diagram of two-flavour QCD at small chemical potentials involves…
We discuss a Lattice QCD mixed action investigation employing Wilson maximally twisted mass sea and overlap valence fermions. Using four values of the lattice spacing, we demonstrate that the overlap Dirac operator assumes a point-like…
We study the color-flavor locked phase of QCD with three massless quarks at high chemical potential and small non zero temperatures. We make use of the recently introduced effective action to describe such a phase. We obtain the exact order…
Lattice QCD calculations with different staggered valence and sea quarks can be used to improve determinations of quark masses, Gasser-Leutwyler couplings, and other parameters relevant to phenomenology. We calculate the masses and decay…
The Banks--Casher relation links the spontaneous breaking of chiral symmetry in QCD to the presence of a non-zero density of quark modes at the low end of the spectrum of the Dirac operator. Spectral observables like the number of modes in…
We describe the low energy excitations of the diquark condensates in the color-flavor locked phase of QCD with three massless flavors, at high baryon densities, in terms of a non-linear effective lagrangian. Such a lagrangian is formally…
The mass sensitivity of the chiral phase transition of QCD with and without axial $U_A(1)$-symmetry breaking at vanishing and finite quark chemical potential is investigated. To focus on the low-energy sector of QCD, a quark-meson model…
We investigate the finite-temperature phase structure and the scaling of the chiral condensate in lattice QCD with two degenerate light quarks, using a renormalization group improved gauge action and the Wilson quark action. We obtain a…
We measure the low lying eigenmodes of an overlap Dirac operator on 2--flavor staggered configurations. By comparing the eigenmode distribution to the predictions of Random Matrix Theory we test to what accuracy staggered configurations…
The relation between the chiral quark condensate in QCD sum rules and chiral perturbation theory is clarified with the help of a low-energy theorem for the scalar and pseudoscalar correlation functions. It is found that the quark condensate…
We introduce a random matrix model with the symmetries of QCD with two colors at nonzero isospin and baryon chemical potentials and temperature. We analyze its phase diagram and find phases with condensation of pion and diquark states in…
The electroweak symmetry breaking and origin of masses may be attributed to the breakdown of chiral symmetry due to a strong gauge dynamics. Among several candidates of such gauge systems, we focus on two-color QCD with $N_f=6$ massless…
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…