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Related papers: Wilson Fermion Determinant in Lattice QCD

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The expectation value of the complex phase factor of the fermion determinant is computed to leading order in the $p$-expansion of the chiral Lagrangian. The computation is valid for $\mu<m_\pi/2$ and determines the dependence of the sign…

High Energy Physics - Lattice · Physics 2008-11-26 K. Splittorff , J. J. M. Verbaarschot

Quenched lattice QCD calculations with Wilson-type fermions at small quark masses are impeded by exceptional configurations. We show how this problem can be resolved in a practicable way without changing the physics in the chiral limit.

High Energy Physics - Lattice · Physics 2008-11-26 M. Göckeler , A. Hoferichter , R. Horsley , D. Pleiter , P. Rakow , G. Schierholz , P. Stephenson

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…

The ${\rm SU}(3)$ pure gauge theory exhibits a first-order thermal deconfinement transition due to spontaneous breaking of its global $Z_3$ center symmetry. When heavy dynamical quarks are added, this symmetry is broken explicitly and the…

High Energy Physics - Lattice · Physics 2021-01-25 Francesca Cuteri , Owe Philipsen , Alena Schön , Alessandro Sciarra

The contributions of scalars and fermions to the null polygonal bosonic Wilson loops/gluon MHV scattering amplitudes in $\mathcal{N} = 4$ SYM are considered. We first examine the re-summation of scalars at strong coupling. Then, we…

High Energy Physics - Theory · Physics 2018-07-19 Alfredo Bonini , Davide Fioravanti , Simone Piscaglia , Marco Rossi

Using two-color lattice QCD with Wilson fermions, we report a study of the finite baryon number density system with two-flavors. First we investigate the Polyakov line and thermodynamical uantities in the $(\kappa,\mu)$ plane, where…

High Energy Physics - Lattice · Physics 2016-09-01 Shin Muroya , Atsushi Nakamura , Chiho Nonaka

We present results of an ongoing study of two flavour QCD with Wilson fermions at finite temperature. We have used tree level Symanzik improvement in both the gauge and fermion part of the action. The phase diagram was previously determined…

High Energy Physics - Lattice · Physics 2009-10-31 F. Karsch , E. Laermann , M. Oevers , P. Schmidt

We present results on the nucleon electromagnetic form factors from Lattice QCD at momentum transfer up to about $12$~GeV$^2$. We analyze two gauge ensembles with the Wilson-clover fermion action, a lattice spacing of $a\approx 0.09$~fm and…

High Energy Physics - Lattice · Physics 2018-10-11 Christos Kallidonis , Sergey Syritsyn , Michael Engelhardt , Jeremy Green , Stefan Meinel , John Negele , Andrew Pochinsky

A serious difficulty in conventional lattice field theory calculations is the coupling between the chiral and continuum limits. With both staggered and Wilson fermions, the chiral limit cannot be realized without first taking the limit of…

The problem of unphysical zero modes in lattice QCD with Wilson fermions can be solved in a clean way by including a mass term proportional to $i \psibar \gamma_5 \tau^3 \psi$ in the standard lattice theory with Nf=2 mass degenerate Wilson…

High Energy Physics - Lattice · Physics 2015-06-25 Roberto Frezzotti , Pietro Antonio Grassi , Stefan Sint , Peter Weisz

We explore the possibility of computing fermionic correlators on the lattice by combining a domain decomposition with a multi-level integration scheme. The quark propagator is expanded in series of terms with a well defined hierarchical…

High Energy Physics - Lattice · Physics 2016-05-18 Marco Cè , Leonardo Giusti , Stefan Schaefer

We present results of a lattice simulation of quantum chromodynamics with two degenerate flavors of dynamic Wilson fermions at $6/g^2=5.3$ at each of two dynamical fermion hopping parameters, $\kappa=0.1670$ and 0.1675, corresponding to…

High Energy Physics - Lattice · Physics 2009-10-22 K. M. Bitar

We simulate lattice QCD at finite quark-number chemical potential to study nuclear matter, using the complex Langevin equation (CLE). The CLE is used because the fermion determinant is complex so that standard methods relying on importance…

High Energy Physics - Lattice · Physics 2018-04-18 D. K. Sinclair , J. B. Kogut

We investigate high density state of SU(2) QCD in the case of the Wilson fermions with Iwasaki improved action. Based on the Woodbery formula, the ratio of fermion determinants is evaluated at each step of the Metropolis link update. At…

High Energy Physics - Lattice · Physics 2007-05-23 S. Muroya , A. Nakamura , C. Nonaka

We propose a method to compute the Wilson coefficients of the weak effective Hamiltonian to all orders in the strong coupling constant using Lattice QCD simulations. We perform our calculations adopting an unphysically light weak boson mass…

High Energy Physics - Lattice · Physics 2018-04-25 Mattia Bruno , Christoph Lehner , Amarjit Soni

We formulate lattice fermions in a way that encompasses Wilson fermions as well as the static and non-relativistic approximations. In particular, we treat $m_qa$ systematically ($m_q$ is the fermion mass) showing how to understand the…

High Energy Physics - Lattice · Physics 2009-10-22 Andreas S. Kronfeld

We determine the masses, the singlet and octet decay constants as well as the anomalous matrix elements of the $\eta$ and $\eta^\prime$ mesons in $N_f=2+1$ QCD\@. The results are obtained using twenty-one CLS ensembles of non-perturbatively…

High Energy Physics - Lattice · Physics 2021-08-27 Gunnar S. Bali , Vladimir Braun , Sara Collins , Andreas Schäfer , Jakob Simeth

The severity of the sign problem in lattice QCD at nonzero baryon density is measured by the average phase of the fermion determinant. Motivated by the equivalence of chiral random matrix theory and QCD to leading order in the epsilon…

High Energy Physics - Lattice · Physics 2010-11-05 Jacques Bloch , Tilo Wettig

In calculating hadronic contributions to precision observables for tests of the Standard Model in lattice QCD, the electromagnetic current plays a central role. Using a Wilson action with O($a$) improvement in QCD with $N_{\mathrm{f}}$…

High Energy Physics - Lattice · Physics 2019-02-20 Antoine Gerardin , Tim Harris , Harvey B. Meyer

We suggest that the lattice Dirac spectra in QCD at finite temperature may be understood using a gaussian unitary ensemble for Wilson fermions, and a chiral gaussian unitary ensemble for Kogut-Susskind fermions. For Kogut-Susskind fermions,…

High Energy Physics - Phenomenology · Physics 2009-10-28 Maciej A. Nowak , Gábor Papp , Ismail Zahed