Related papers: Dynamical twisted mass fermions
We report on recent progress in the calculation of the 3-loop massive Wilson coefficients in deep-inelastic scattering at general values of $N$ for neutral and charged current reactions in the asymptotic region $Q^2 \gg m^2$. Four new out…
At stronger gauge-field couplings, the domain wall fermion (DWF) residual mass, a measure of chiral symmetry breaking, grows rapidly. This measure is largely due to near zero fermion eigenmodes of logarithm of the 4D transfer matrix along…
We explore and compare three mixed action setups with Wilson twisted mass sea quarks and different valence quark actions: (1) Wilson twisted mass, (2) Wilson twisted mass + clover and (3) Wilson + clover. Our main goal is to reduce lattice…
We compute the low lying eigenvalues of the Hermitian Dirac operator in lattice QCD with $N_{\rm f} = 2+1+1$ twisted mass fermions. We discuss whether these eigenvalues are in the $\epsilon$-regime or the $p$-regime of Wilson chiral…
We study chiral symmetry breaking in $\rm QED_3$ with $N_f$ flavors of four-component fermions. A closed system of Schwinger-Dyson equations for fermion and photon propagators and the full fermion-photon vertex is proposed, which is…
Lattice studies of gauge theories with symplectic gauge groups provide valuable information about gauge dynamics, and complement the results of lattice investigations focused on unitary gauge groups. These theories play a central role in…
We present a first lattice QCD calculation of the transverse-momentum-dependent wave functions (TMDWFs) of the pion using large-momentum effective theory. Numerical simulations are based on one ensemble with 2+1+1 flavors of highly improved…
We explore aspects of the phase structure of SU(2) and SU(3) lattice gauge theories at strong coupling with many flavours $N_f$ of Wilson fermions in the fundamental representation, including the relevance to recent searches for a conformal…
We introduce a mixed-action approach based on CLS ensembles, where a valence $N_f$=2+1+1 Twisted Mass QCD action is combined with the $N_f$=2+1 non-perturbatively O$(a)$-improved Wilson sea sector. We show that for maximally twisted valence…
We investigate the distribution of low-lying eigenmodes of hermitian Wilson-Dirac operator, $H_W$, with the gauge action whose form is designed to avoid topology change, as well as with the standard plaquette action. On the quenched…
We investigate how a dynamical mass of a fermion is affected by a topological mass of a gauge field in a Maxwell-Chern-Simons $QED_3$ coupled with a two-component fermion. The dynamical mass and also a parity condensate are estimated by…
We experiment with adding dynamical gauge field to Kaplan (defect) fermions. In the case of U(1) gauge theory we use an inhomogenous Higgs mechanism to restrict the 3d gauge dynamics to a planar 2d defect. In our simulations the 3d theory…
Motivated by recent measurements at J-Lab, the pion electromagnetic form-factor is investigated with quenched domain wall fermions and a renormalization group improved gauge action called DBW2. We see that quark mass dependence of the…
We present selected results obtained by RQCD from simulations of $N_f=2+1$ flavours of non-perturbatively $\mathcal{O}(a)$ improved Wilson fermions, employing open boundary conditions in time. The ensembles were created within the CLS…
We report preliminary results for 2D massive QED with two flavours of Wilson fermions, using the Hermitean variant of L\"uscher's bosonization technique. The chiral condensate and meson masses are obtained. The simplicity of the model…
We report on the status of an update of our collaboration's previous computation of light and strange quark masses in QCD with $N_{f}=2+1$ dynamical flavours. Bare quark masses are extracted from CLS ensembles, using $O(a)$-improved Wilson…
We review our recent results on the infrared behaviour of the SU(2) gauge theory with $N_f$ massless fundamental flavour fermions. We have analyzed the running of the coupling in SU(2) gauge theories with six and eight fermionic flavours…
Perturbative and non-perturbative results on the renormalization constants of the fermion field and the twist-2 fermion bilinears are presented with emphasis on the non-perturbative evaluation of the one-derivative twist-2 vector and axial…
We calculate the tree-level mass spectrum for a linear sigma model describing the scalar and pseudoscalar mesons of a $SU(3)$ local gauge theory with Dirac fermions in the fundamental representation. $N_1$ fermions have a mass $m_1$ and…
We compare lattice scales determined from the vector meson mass and the Wilson flow scale w_0 in QCD with two-flavours of rooted naive staggered fermions over a wide range of lattice spacing and quark mass. We find that the distributions of…