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Related papers: O(a^2) cutoff effects in Wilson fermion simulation…

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We report on lattice QCD results for the thermodynamic equation of state of quark-gluon matter obtained with Nf=2 degenerate quark flavors. For the fermion field discretization we are using the Wilson-twisted mass prescription. Simulations…

High Energy Physics - Lattice · Physics 2015-06-23 F. Burger , E. -M. Ilgenfritz , M. P. Lombardo , M. Muller-Preussker

We have explored twisted mass LQCD (tmLQCD) analytically using chiral perturbation theory, including discretization effects up to O(a^2), and working at next-to-leading (NLO) order in the chiral expansion. In particular we have studied the…

High Energy Physics - Lattice · Physics 2009-11-10 Stephen R. Sharpe , Jackson M. S. Wu

Background field methods provide an important nonperturbative formalism for the determination of hadronic properties which are complementary to matrix-element calculations. However, new challenges are encountered when utilising a fermion…

High Energy Physics - Lattice · Physics 2020-05-20 Ryan Bignell , Waseem Kamleh , Derek Leinweber

We present results for the strange contribution to the electromagnetic form factors of the nucleon computed on the CLS ensembles with $N_f=2+1$ flavors of $\mathcal{O}(a)$-improved Wilson fermions and an $\mathcal{O}(a)$-improved vector…

High Energy Physics - Lattice · Physics 2019-12-10 Dalibor Djukanovic , Konstantin Ottnad , Jonas Wilhelm , Hartmut Wittig

We investigate the 2-flavor QCD with non-degenerate quark masses at low-energy, using the chiral perturbation theory including the $\eta$ meson and anomaly effects. For the fixed $m_d\not=0$, the neutral pion becomes massless at two values…

High Energy Physics - Lattice · Physics 2015-04-08 Sinya Aoki , Michael Creutz

QCD thermodynamics is considered using Wilson fermions in the fixed scale approach. The temperature dependence of the renormalized chiral condensate, quark number susceptibility and Polyakov loop is measured at four lattice spacings…

High Energy Physics - Lattice · Physics 2015-06-05 S. Borsanyi , S. Durr , Z. Fodor , C. Hoelbling , S. D. Katz , S. Krieg , D. Nogradi , B. C. Toth , N. Trombitas , K. K. Szabo

Discretisation errors in two-flavour lattice QCD with Wilson-quarks and DBW2 gauge action are investigated by comparing numerical simulation data at two values of the bare gauge coupling. Both non-zero and zero twisted mass values are…

High Energy Physics - Lattice · Physics 2009-01-07 F. Farchioni , P. Hofmann , K. Jansen , I. Montvay , G. Muenster , E. E. Scholz , L. Scorzato , A. Shindler , N. Ukita , C. Urbach , U. Wenger , I. Wetzorke

We determine the quark mass ratio m_c/m_s on the lattice, using Wilson-type fermions. Configurations with N_f=2 dynamical clover-improved fermions by the QCDSF collaboration are used, which were made available through the ILDG. In the…

High Energy Physics - Lattice · Physics 2013-05-30 Stephan Durr , Giannis Koutsou

We compute the hadron mass spectrum, the quark masses and the meson decay constants in quenched lattice QCD with non-perturbatively $O(a)$ improved Wilson fermions. The calculations are done for two values of the coupling constant, $\beta =…

High Energy Physics - Lattice · Physics 2008-11-26 M. Göckeler , R. Horsley , H. Perlt , P. Rakow , G. Schierholz , A. Schiller , P. Stephenson

The pion-mass dependence of the nucleon mass within the covariant SU(2) baryon chiral perturbation theory both without and with explicit Delta(1232) degrees of freedom up to order p^4 is investigated. By fitting to lattice QCD data in 2 and…

High Energy Physics - Phenomenology · Physics 2013-10-18 L. Alvarez-Ruso , T. Ledwig , J. Martin Camalich , M. J. Vicente-Vacas

To date numerical simulations of lattice QCD have not found a chiral phase transition of first order which is expected to occur for sufficiently light pions. We show how the restoration of an exact global chiral symmetry can strongly…

High Energy Physics - Phenomenology · Physics 2024-07-25 Robert D. Pisarski , Fabian Rennecke

We discuss insights that may be drawn from our recent 2 flavour O(a)--improved Wilson quark simulations. We discuss the evidence of the onset of chiral logarithms in the pion decay constant. An overview is given of current extrapolation…

High Energy Physics - Lattice · Physics 2007-05-23 S. V. Wright

We present a lattice QCD calculation of the double-virtual neutral pion transition form factor, with the goal to cover the kinematic range relevant to hadronic light-by-light scattering in the muon $g-2$. Several improvements have been made…

High Energy Physics - Lattice · Physics 2019-09-26 Antoine Gérardin , Harvey B. Meyer , Andreas Nyffeler

Domain model of QCD allows for description of wide range of meson observables, dynamical chiral symmetry breaking, and resolution of $U_A(1)$ and strong $CP$ problems. The purpose of the present study is transition form-factor of neutral…

High Energy Physics - Phenomenology · Physics 2017-04-26 Sergei Nedelko , Vladimir Voronin

We construct the chiral effective Lagrangian for two lattice theories: one with Wilson fermions and the other with Wilson sea fermions and Ginsparg-Wilson valence fermions. For each of these theories we construct the Symanzik action through…

High Energy Physics - Lattice · Physics 2011-05-05 Oliver Baer , Gautam Rupak , Noam Shoresh

We study the pion form factor F^{\pi \gamma\gamma^*}(Q^2) in the light-cone sum rule approach, accounting for radiative corrections and higher twist effects. Comparing the results to the CLEO experimental data on F^{\pi…

High Energy Physics - Phenomenology · Physics 2016-09-06 Alexander Schmedding , Oleg Yakovlev

The electromagnetic form factors provide important insight into the internal structure of the nucleon and continue to be of major interest for experiment and phenomenology. For an intermediate range of momenta the form factors can be…

We present analytical results to guide numerical simulations with Wilson fermions in higher representations of the colour group. The ratio of $\Lambda$ parameters, the additive renormalization of the fermion mass, and the renormalization of…

High Energy Physics - Lattice · Physics 2008-11-26 Luigi Del Debbio , Mads T. Frandsen , Haralambos Panagopoulos , Francesco Sannino

We study the thermal transition of QCD with two degenerate light flavours by lattice simulations using $\mathcal{O}(a)$-improved Wilson quarks. Particular emphasis lies on the pattern of chiral symmetry restoration, which we probe via the…

High Energy Physics - Lattice · Physics 2019-04-05 Bastian B. Brandt , Marco Cè , Anthony Francis , Tim Harris , Harvey B. Meyer , Owe Philipsen , Hartmut Wittig

In this proceeding contribution we report on the ongoing effort to simulate Wilson-type fermions in the so called epsilon regime of chiral perturbation theory. We present results for the chiral condensate and the pseudoscalar decay constant…

High Energy Physics - Lattice · Physics 2010-11-05 K. Jansen , A. Shindler