Related papers: I=2 $\pi$-$\pi$ scattering length with dynamical o…
We calculate the 2-loop partition function of QCD on the lattice, using the Wilson formulation for gluons and the overlap-Dirac operator for fermions. Direct by-products of our result are the 2-loop free energy and average plaquette. Our…
We study forward and backward pi-pi scattering within a QCD model based on the Dyson--Schwinger, Bethe--Salpeter equations truncated to the rainbow-ladder level. Our microscopic relativistic quark formulation preserves chiral symmetry and…
The overlap hypercube fermion is a variant of a chirally symmetric lattice fermion, which is endowed with a higher level of locality than the standard overlap fermion. We apply this formulation in quenched QCD simulations with light quarks.…
Elastic $I=1/2$, $s$- and $p$-wave $K\pi$ scattering amplitudes are simultaneously calculated using a L\"uscher style analysis on a single ensemble of dynamical Wilson-clover fermions at $m_\pi \sim 230$ MeV. Partial wave mixing due to the…
The elastic $I=1/2$, $s$- and $p$-wave kaon-pion scattering amplitudes are calculated using a single ensemble of anisotropic lattice QCD gauge field configurations with $N_{\mathrm{f}} = 2+1$ flavors of dynamical Wilson-clover fermions at…
We simulate K pi scattering in s-wave and p-wave for both isospins I=1/2, 3/2 using quark-antiquark and meson-meson interpolating fields. We extract the elastic phase shifts delta at several values of the K-pi relative momenta. The…
We analyze recent results on isoscalar $\pi\pi$ scattering from a $N_f=2+1$ lattice simulation by the HadronSpectrum collaboration by re-summing the two-flavor chiral scattering amplitude of the next-to-leading order in the so-called…
We compute the chiral condensate in 2+1-flavor QCD through the spectrum of low-lying eigenmodes of Dirac operator. The number of eigenvalues of the Dirac operator is evaluated using a stochastic method with an eigenvalue filtering technique…
We explore application of the domain wall fermion formalism of lattice QCD to calculate the $K\to\pi\pi$ decay amplitudes in terms of the $K\to\pi$ and $K\to 0$ hadronic matrix elements through relations derived in chiral perturbation…
We report on simulation results with overlap hypercube fermions (overlap HF) - a type of exactly chiral lattice fermions - and their link to chiral perturbation theory. We first sketch the construction of the overlap HF and discuss its high…
Our previous calculations of the sea- and valence-quark mass dependence of the pseudoscalar meson masses and decay constants is repeated on a 16^3x32 lattice which allows for a better determination of the quantities in question. The…
Recent developments in lattice QCD calculation of flavor singlet nucleon matrix elements are reviewed. Substantial sea quark contributions are found in the $\pi$-$N\ \sigma$ term and the quark spin content of the nucleon such that the total…
We calculate the nucleon sigma term in two-flavor lattice QCD utilizing the Feynman-Hellman theorem. Both sea and valence quarks are described by the overlap fermion formulation, which preserves exact chiral and flavor symmetries on the…
We use lattice field theory to study the finite-volume energy spectrum of the $\pi\pi$ system in $SU(2)$ chiral effective field theory (ChEFT) at leading order in the chiral expansion. \hl{This finite-volume spectrum can be directly related…
We study the correction to the radiative $\pi^0$ decay width due to finite light quark mass. Using lattice QCD with the overlap fermion formulation, we calculate the three-point function of the form $<PV_\mu V_\nu>$ in the (Euclidean)…
We report on the first lattice calculation of the QCD phase transition using chiral fermions at physical values of the quark masses. This calculation uses 2+1 quark flavors, spatial volumes between (4 fm$)^3$ and (11 fm$)^3$ and…
We present continuum and lattice calculations for elastic scattering between a fermion and a bound dimer in the shallow binding limit. For the continuum calculation we use the Skorniakov-Ter-Martirosian (STM) integral equation to determine…
Scaling behavior is analyzed for the two-flavor QCD lattice gauge theory chiral transition. Leading scaling behavior and correction to leading scaling from lattice spacing effects are examined for the quark condensate. Scaling predictions…
We investigate how the topological charge density in lattice QCD simulations is affected by violations of chiral symmetry caused by the fermion action. To this end we compare lattice configurations generated with a number of different…
We simulate quenched QCD with the overlap Dirac operator. We work with the Wilson gauge action at beta=6 on an 18^3x64 lattice. We calculate quark propagators for a single source point and quark mass ranging from am_q=0.03 to 0.75. We…