Related papers: Improved Effective Action for Light Quarks Beyond …
In this talk we discuss an improvement of the Diakonov-Petrov QCD Effective Action. We propose the Improved Effective Action, which is derived on the basis of the Lee-Bardeen results for the quark determinant in the instanton field. The…
We present results for the spectrum of light and strange mesons on configurations with two flavors of mass-degenerate Chirally Improved sea quarks. The calculations are performed on seven ensembles of lattice size 16^3x32 at three different…
The scale dependence of an effective average action for mesons and quarks is described by a nonperturbative flow equation. The running couplings lead to spontaneous chiral symmetry breaking. We argue that for strong Yukawa coupling between…
We discuss the constraint on the size of QCD instanton effects in low-energy effective theory. Among various instanton effects in meson mass spectrum and dynamics, we concentrate on the instanton-induced masses of light quarks. The famous…
The fermion determinant in an instanton background for a quark field of arbitrary mass is determined exactly using an efficient numerical method to evaluate the determinant of a partial wave radial differential operator. The bare sum over…
We present the final results of the JLQCD calculation of the light hadron spectrum and quark masses with two flavors of dynamical quarks using the plaquette gauge action and fully $O(a)$-improved Wilson quark action at $\beta=5.2$. We…
As a successive work to [Phys.Rev.D 102 (2020), 034034], we derive the $1/m_Q$ corrections to chiral effective Lagrangian for heavy-light mesons from QCD under proper approximations. The low energy constants in the effective Lagrangian are…
A straightforward algebraic derivation is carried out of light quark propagator and effective action in the instanton-anti-instanton molecule. Exact expressions are obtained which contain contributions of all quark modes. Possible…
We use improved lattice actions for glue, light quarks and heavy quarks for which we use lattice NRQCD to compute hadron masses. Our results are in good agreement with experiment, except for charmed hadrons. It seems that charmed quar ks…
The precise quark mass dependence of the one-loop effective action in an instanton background has recently been computed [arXiv:hep-th/0410190]. The result interpolates smoothly between the previously known extreme small and large mass…
We derive an effective action combining chiral and heavy quark symmetry, using approximate bosonization techniques of QCD. We explicitly show that the heavy-quark limit is compatible with the large $N_c$ (number of color) limit in the meson…
An interesting class of background field configurations in QED are the O(2)xO(3) symmetric fields. Those backgrounds have some instanton-like properties and yield a one-loop effective action that is highly nontrivial but amenable to…
We present in this talk the recent investigation of the effective weak chiral Lagrangian within the framework of the instanton-induced chiral quark model. The low energy constants in leading order $g_8$ and $g_{27}$, and their ratio are…
The quark determinant in the presence of a background gluon field is calculated in a large quark mass approach within a derivative expansion by considering quark sources. The resulting low-energy QCD Effective Field Theory (EFT) is valid…
The chirally improved (CI) fermion action allows us to obtain results for pion masses down to 320 MeV on (in lattice units) comparatively small lattices with physical extent of 2.4 fm. We use differently smeared quarks sources to build sets…
We present results for the light quark masses for the Wilson quark action obtained with the PCAC relation for the one-link extended axial vector current in quenched QCD at $\beta=5.9-6.5$. This method leads to a remarkable improvement of…
In this talk it is discussed the derivation of low-frequencies part of quark determinant and partition function. As a first application, quark condensate is calculated beyond chiral limit with the account of O(m), O(1/N_c), O(1/N_c m) and…
Recently, the Fermilab heavy-quark action was extended to include dimension-six and -seven operators in order to reduce the discretization errors. In this talk, we present results of the first numerical simulations with this action (the OK…
Recently a new caculational scheme for effective actions in radial background fields was developed. The effective action is expressed as an infinite sum of partial-wave contributions, using the rotational symmetry of the system. The sum…
We investigate light hadron spectroscopy with an improved quenched staggered quark action. We compare the results obtained with an improved gauge plus an improved quark action, an improved gauge plus standard quark action, and the standard…