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Related papers: Mixed action simulations: approaching physical qua…

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We present a performance comparison of the Kramers equation and the boson algorithms for simulations of QCD with two flavors of dynamical Wilson fermions and gauge group $SU(2)$. Results are obtained on $6^312$, $8^312$ and $16^4$ lattices.…

High Energy Physics - Lattice · Physics 2009-10-28 Karl Jansen , Beat Jegerlehner , Chuan Liu

We report on first results of an ongoing effort to simulate lattice QCD with two degenerate flavours of quarks by means of the twisted mass formulation tuned to maximal twist. By utilising recent improvements of the HMC algorithm,…

High Energy Physics - Lattice · Physics 2008-11-26 Karl Jansen , Carsten Urbach , ETM Collaboration

We show that maximally twisted mass fermions can be employed to regularize on the lattice the fully unquenched QCD+QED theory with vanishing $\theta$-term. We discuss how the critical mass of the up and down quarks can be conveniently…

High Energy Physics - Lattice · Physics 2016-12-08 Roberto Frezzotti , Giancarlo Rossi , Nazario Tantalo

We present numerical simulation of QCD with two dynamical quark flavors described by the overlap fermion action on a $16^3\times 32\times (0.12 {\rm fm})^4$ lattice. We calculate pseudo-scalar masses and decay constants and investigate…

High Energy Physics - Lattice · Physics 2009-04-14 J. Noaki , S. Aoki , H. Fukaya , S. Hashimoto , T. Kaneko , H. Matsufuru , T. Onogi , E. Shintani , N. Yamada

We explore sea quark effects in the light hadron mass spectrum in a simulation of two-flavor QCD using the nonperturbatively O(a)-improved Wilson fermion action. In order to identify finite-size effects, light meson masses are measured on…

It is shown how on-shell O(a) improvement can be implemented non-perturbatively in lattice QCD with Wilson quarks. Improvement conditions are obtained by requiring the PCAC relation to hold exactly in certain matrix elements. These are…

High Energy Physics - Lattice · Physics 2009-10-28 M. Lüscher , S. Sint , R. Sommer , P. Weisz , H. Wittig , U. Wolff

I report on recent progress and future prospects for lattice QCD calculations relevant for flavour physics and CP violation. I will focus on lattice studies that incorporate realistic vacuum polarization effects, i.e., with n_f=2+1 sea…

High Energy Physics - Phenomenology · Physics 2008-07-06 Elvira Gamiz

We present the first lattice QCD calculation of the $B_s$ and $B_d$ mixing parameters with physical light quark masses. We use MILC gluon field configurations that include $u$, $d$, $s$ and $c$ sea quarks at 3 values of the lattice spacing…

High Energy Physics - Lattice · Physics 2014-11-26 R. J. Dowdall , C. T. H. Davies , R. R. Horgan , G. P. Lepage , C. J. Monahan , J. Shigemitsu

We present a technique designed for parallelizing large rigid body simulations, capable of exploiting multiple CPU cores within a computer and across a network. Our approach can be applied to simulate both unilateral and bilateral…

Graphics · Computer Science 2024-03-27 Manas Kale , Paul G. Kry

Electromagnetic effects play an important role in many phenomena such as isospin-symmetry breaking in the hadron spectrum and the hadronic contributions to g-2. We have generalized the MILC QCD code to include the electromagnetic field. In…

High Energy Physics - Lattice · Physics 2014-11-18 Ran Zhou , Steven Gottlieb

A status report is made of an on-going full QCD study on the CP-PACS aiming at a comparative analysis of the effects of improving gauge and quark actions on hadronic quantities and static quark potential. Simulations are made for four…

High Energy Physics - Lattice · Physics 2009-10-30 S. Aoki , G. Boyd , R. Burkhalter , S. Hashimoto , N. Ishizuka , Y. Iwasaki , K. Kanaya , T. Kaneko , Y. Kuramashi , M. Okawa , A. Ukawa , T. Yoshié

We evaluate pseudoscalar, vector, spin 1/2 and spin 3/2 baryon masses predicted by lattice QCD with Wilson quarks in the valence (quenched) approximation for a range of different values of lattice spacing, lattice volume and quark mass.…

High Energy Physics - Lattice · Physics 2009-10-22 F. Butler , H. Chen , J. Sexton , A. Vaccarino , D. Weingarten

We discuss the impact of various improvements on simulations of dynamical overlap fermions using the Hybrid Monte Carlo algorithm. We focus on the usage of fat links and multiple pseudo-fermion fields.

High Energy Physics - Lattice · Physics 2011-07-18 Thomas DeGrand , Stefan Schaefer

We present first results for the pseudoscalar decay constants $f_K$, $f_D$ and $f_{D_s}$ from lattice QCD with N_f=2+1+1 flavours of dynamical quarks. The lattice simulations have been performed by the European Twisted Mass collaboration…

High Energy Physics - Lattice · Physics 2010-12-02 Federico Farchioni , Gregorio Herdoiza , Karl Jansen , Marcus Petschlies , Carsten Urbach , ETM collaboration

In this letter we give the equation of state of QCD at finite temperatures and densities. The recently proposed overlap improving multi-parameter reweighting technique is used to determine observables at nonvanishing chemical potentials.…

High Energy Physics - Lattice · Physics 2008-11-26 Z. Fodor , S. D. Katz , K. K. Szabo

FLIC overlap fermions are a variant of the standard (Wilson) overlap action, with the FLIC (Fat Link Irrelevant Clover) action as the overlap kernel rather than the Wilson action. The structure of the FLIC overlap fermion propagator in…

High Energy Physics - Lattice · Physics 2010-03-04 Waseem Kamleh , Patrick O. Bowman , Derek B. Leinweber , Anthony G. Williams , Jianbo Zhang

We study properties of the thermal transition in QCD, using anisotropic, fixed-scale lattice simulations with $N_f = 2+1$ flavours of Wilson fermion. Observables are compared for two values of the pion mass, focusing on chiral properties.…

High Energy Physics - Lattice · Physics 2020-07-09 G. Aarts , C. Allton , J. Glesaaen , S. Hands , B. Jäger , S. Kim , M. P. Lombardo , A. A. Nikolaev , S. M. Ryan , J. -I. Skullerud , L. -K. Wu

Nuclear forces and hyperon forces are studied by lattice QCD. Simulations are performed with (almost) physical quark masses, $m_\pi \simeq 146$ MeV and $m_K \simeq 525$ MeV, where $N_f=2+1$ nonperturbatively ${\cal O}(a)$-improved Wilson…

We construct new Ginsparg-Wilson fermions for QCD by inserting an approximately chiral Dirac operator - which involves ingredients of a perfect action - into the overlap formula. This accelerates the convergence of the overlap Dirac…

High Energy Physics - Lattice · Physics 2010-04-05 W. Bietenholz

I report recent results from full QCD simulations by CP-PACS and JLQCD collaborations.

High Energy Physics - Lattice · Physics 2008-11-26 Sinya Aoki