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Related papers: Simulating dynamical fermions with smeared links

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Smearing the gauge links of dynamical configurations removes small scale unphysical vacuum fluctuations und thus improves the chiral properties of lattice fermions. We present a new algorithm for the simulation of dynamical fermions coupled…

High Energy Physics - Lattice · Physics 2015-06-25 A. Hasenfratz , F. Knechtli

Staggered fermions with smeared links can have greatly improved chiral properties. In a recent paper we introduced a simple and effective method to simulate four flavors of staggered smeared link fermions. In this work we extend the four…

High Energy Physics - Lattice · Physics 2007-05-23 Anna Hasenfratz , Francesco Knechtli

We performed dynamical simulations with HYP smeared staggered fermions using the recently proposed partial-global stochastic Metropolis algorithm with fermion matrix reduction and determinant breakup improvements. In this paper we discuss…

High Energy Physics - Lattice · Physics 2009-11-07 Andrei Alexandru , Anna Hasenfratz

One of the most serious problems of the staggered fermion lattice action is flavor symmetry violation. Smeared link staggered fermions can improve flavor symmetry by an order of magnitude relative to the standard thin link action. Over the…

High Energy Physics - Lattice · Physics 2009-11-07 Anna Hasenfratz

We present and test a new method for simulating dynamical fermions with fat links. Our construction is based on the introduction of auxiliary but dynamical gauge fields and works with any fermionic action and can be combined with any…

High Energy Physics - Lattice · Physics 2009-10-31 F. Knechtli , A. Hasenfratz

We introduce a new smearing transformation, the hypercubic (HYP) fat link. The hypercubic fat link mixes gauge links within hypercubes attached to the original link only. Using quenched lattices at beta = 5.7 and 6.0 we show that HYP fat…

High Energy Physics - Lattice · Physics 2009-11-07 A. Hasenfratz , F. Knechtli

We present results from simulations of two dynamical flavors of improved Wilson fermions with nHYP smeared gauge links. We demonstrate that the simulation is stable at a pseudo-scalar mass of 360MeV, a 2.1fm box and a lattice spacing of…

High Energy Physics - Lattice · Physics 2009-04-14 Anna Hasenfratz , Roland Hoffmann , Stefan Schaefer

We study the impact of hypercubic (HYP) smearing on the size of taste breaking for staggered fermions, comparing to unimproved and to asqtad-improved staggered fermions. As in previous studies, we find a substantial reduction in…

High Energy Physics - Lattice · Physics 2008-11-26 Taegil Bae , David H. Adams , Chulwoo Jung , Hyung-Jin Kim , Jongjeong Kim , Kwangwoo Kim , Weonjong Lee , Stephen R. Sharpe

We extend our previous study of taste-symmetry breaking using HYP-smeared staggered fermions in two ways. First, we improve the statistics of a comparison of unimproved and HYP-smeared staggered fermions on quenched lattices with $a\approx…

High Energy Physics - Lattice · Physics 2008-11-26 Taegil Bae , David Adams , Chulwoo Jung , Hyung-Jin Kim , Jongjeong Kim , Kwangwoo Kim , Weonjong Lee , Stephen R. Sharpe

We investigate a variant of hypercubic gauge link smearing where the SU(3) projection is replaced with a normalization to the corresponding unitary group. This smearing is differentiable and thus suitable for use in dynamical fermion…

High Energy Physics - Lattice · Physics 2010-10-27 Anna Hasenfratz , Roland Hoffmann , Stefan Schaefer

The chiral properties of lattice fermions can be improved by altering either their fermion-gauge coupling or the pure gauge part of the action (or both). Using both perturbation theory and nonperturbative simulation, we compare a simple…

High Energy Physics - Lattice · Physics 2016-09-01 Thomas DeGrand , Anna Hasenfratz , Tamas G. Kovacs

We study the finite temperature phase transition of four flavor staggered fermions with hypercubic fat link actions on N_t=4 and N_t=6 temporal lattices. Our fat links are constructed with hypercubic blocking (HYP) and therefore are very…

High Energy Physics - Lattice · Physics 2007-05-23 A. Hasenfratz , F. Knechtli

We report on recent progress in employing the Highly Improved Staggered Quark (HISQ) action introduced by the HPQCD/UKQCD collaboration in simulations with dynamical fermions. The HISQ action is an order $a^2$ Symanzik-improved action with…

High Energy Physics - Lattice · Physics 2010-01-21 A. Bazavov , C. Bernard , C. DeTar , W. Freeman , Steven Gottlieb , U. M. Heller , J. E. Hetrick , J. Laiho , L. Levkova , J. Osborn , R. Sugar , D. Toussaint

We apply non-perturbative renormalization to bilinears composed of improved staggered fermions. We explain how to generalize the method to staggered fermions in a way which is consistent with the lattice symmetries, and introduce a new type…

High Energy Physics - Lattice · Physics 2013-10-18 Andrew T. Lytle , Stephen R. Sharpe

We present results from simulations of two flavors of dynamical overlap fermions on 8^4 lattices at three values of the sea quark mass and a lattice spacing of about 0.16 fm. We measure the topological susceptibility and the chiral…

High Energy Physics - Lattice · Physics 2009-11-11 Thomas DeGrand , Stefan Schaefer

We present recent results from lattice simulations of 2+1 flavors of improved staggered fermions at zero baryon number density near the high temperature crossover. Included are new results from simulations of asqtad fermions at Nt = 12 and…

High Energy Physics - Lattice · Physics 2011-01-27 Wolfgang Söldner

It is well established that lattice artifacts can be suppressed substantially by the use of SU(3)-projected smeared links in the fermion action. An example is the Highly Improved Staggered Quark action where the ASQ-like effective links are…

High Energy Physics - Lattice · Physics 2008-11-26 K. Y. Wong , R. M. Woloshyn

We simulate Quantum Chromodynamics in four Euclidean dimensions with two (degenerate mass) flavors of dynamical quarks. The Dirac operator is the so-called chirally improved operator that has been studied so far in quenched calculations. We…

High Energy Physics - Lattice · Physics 2007-05-23 C. B. Lang , Pushan Majumdar , Wolfgang Ortner

For thermodynamics studies it is desirable to simulate two degenerate flavors and retain at least a remnant of the chiral symmetry. Staggered fermions can achieve this at the cost of rooting the determinant. Rooting can be avoided using…

High Energy Physics - Lattice · Physics 2024-01-17 Reka A. Vig , Szabolcs Borsanyi , Zoltan Fodor , Daniel Godzieba , Paolo Parotto , Chik Him Wong

We present a set of related Hybrid Monte Carlo methods to simulate an arbitrary number of dynamical overlap fermions. Each fermion is represented by a chiral pseudo-fermion field. The new algorithm reduces critical slowing down in the…

High Energy Physics - Lattice · Physics 2009-11-11 Thomas DeGrand , Stefan Schaefer
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