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Related papers: Testing UV-filtered ("fat-link") clover fermions

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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

Updates on results for the electric, magnetic and axial vector form factors are presented. The data analyzed cover high statistics measurements on 11 ensembles generated with 2+1+1 flavors of HISQ fermions by the MILC collaboration. The…

High Energy Physics - Lattice · Physics 2019-02-01 Yong-Chull Jang , Tanmoy Bhattacharya , Rajan Gupta , Huey-Wen Lin , Boram Yoon

We study renormalizable extensions of the standard model that contain vector-like fermions in a (single) complex representation of the standard model gauge group. There are 11 models where the vector-like fermions Yukawa couple to the…

High Energy Physics - Phenomenology · Physics 2015-10-09 Koji Ishiwata , Zoltan Ligeti , Mark B. Wise

The plethora of increasingly precise experiments which hunt for axion-like particles (ALPs), as well as their widely different energy reach, call for the theoretical understanding of ALP couplings at loop-level. We derive the one-loop…

High Energy Physics - Phenomenology · Physics 2021-11-24 J. Bonilla , I. Brivio , M. B. Gavela , V. Sanz

We calculate one-loop matching factors for bilinear operators composed of improved staggered fermions. We compare the results for different improvement schemes used in the recent literature, all of which involve the use of smeared links.…

High Energy Physics - Lattice · Physics 2009-11-07 Weonjong Lee , Stephen R. Sharpe

We calculate spin averaged splittings in the bottomonium and charmonium systems using the clover action. We compare static and kinetic masses of heavy-heavy and heavy-light mesons and discuss the consistency of the results.

High Energy Physics - Lattice · Physics 2010-01-18 Sara Collins , Robert G. Edwards , Urs M. Heller , John Sloan

We present preliminary results from our calculation of the low energy constants (LECs) of the chiral effective theory for 3, 4 and 5 color QCD with $N_f=2$ dynamical fermion flavors. We simulate with clover fermions over a range of lattice…

High Energy Physics - Lattice · Physics 2021-10-22 Evan Wickenden , Thomas DeGrand

We investigate the mass of the $1^{-+}$ exotic meson, created with hybrid interpolating fields. Access to light quark masses approaching 25 MeV is facilitated by the use of the Fat-Link Irrelevant Clover (FLIC) fermion action, and large…

High Energy Physics - Lattice · Physics 2010-03-04 J. N. Hedditch , W. Kamleh , B. G. Lasscock , D. B. Leinweber , A. G. Williams , J. M. Zanotti

We describe a way to optimize the chiral behavior of Wilson-type lattice fermion actions by studying the low energy real eigenmodes of the Dirac operator. We find a candidate action, the clover action with fat links with a tuned clover…

High Energy Physics - Lattice · Physics 2007-05-23 Thomas DeGrand , Anna Hasenfratz , Tamás G. Kovács

State-of-the-art algorithms for simulating fermions coupled to gauge fields often rely on integrating fermion degrees of freedom. While successful in simulating QCD at zero chemical potential, at finite density these approaches are hindered…

High Energy Physics - Lattice · Physics 2024-02-05 Joao C. Pinto Barros , Thea Budde , Marina Krstic Marinkovic

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 present a summary of the full calculation of the axial, scalar and tensor flavor diagonal charges of the nucleon carried out using Wilson-clover fermions on eight ensembles generated using 2+1+1-flavors of highly improved staggered…

High Energy Physics - Lattice · Physics 2024-01-02 Sungwoo Park , Tanmoy Bhattacharya , Rajan Gupta , Huey-Wen Lin , Santanu Mondal , Boram Yoon

We present a study of the pseudoscalar and vector meson form factors, calculated using the Fat-Link Irrelevant Clover (FLIC) action in the framework of Quenched Lattice QCD. Of particular interest is the determination of a negative…

High Energy Physics - Lattice · Physics 2008-11-26 J. N. Hedditch , W. Kamleh , B. G. Lasscock , D. B. Leinweber , A. G. Williams , J. M. Zanotti

We present results for matching factors for staggered four-fermion operators constructed using HYP-smeared fat links both in the action and the operators. We use perturbation theory to calculate the matching factors and work to one-loop…

High Energy Physics - Lattice · Physics 2011-03-10 Jongjeong Kim , Weonjong Lee , Stephen R. Sharpe

We present first results for masses of positive and negative parity excited baryons in lattice QCD using an O(a^2) improved gluon action and a Fat Link Irrelevant Clover (FLIC) fermion action in which only the irrelevant operators are…

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 give some new performance results for the Hybrid Monte Carlo (HMC) simulation of dynamical clover-improved Wilson fermions using an improved pseudo-fermion action. The generalisation of even-odd preconditioning for the standard Wilson…

High Energy Physics - Lattice · Physics 2009-04-25 Martin Hasenbusch

I have performed scaling tests using quenched spectroscopy of a family of fermion actions which have a hypercubic kinetic term, gauge connections built of smeared links, and an anomalous magnetic moment term. These actions show improved…

High Energy Physics - Lattice · Physics 2010-11-19 MILC Collaboration , T. DeGrand

A method for simulating chiral gauge theories on the lattice is proposed, involving zeromodes on a topological defect. Lattice doublers may be decoupled in a gauge invariant manner, and flavor anomalies can be directly observed on a finite…

High Energy Physics - Lattice · Physics 2011-07-19 D. B. Kaplan

We consider recent progress in algorithms for generating gauge field configurations that include the dynamical effects of light fermions. We survey what has been achieved in recent state-of-the-art computations, and examine the trade-offs…

High Energy Physics - Lattice · Physics 2009-11-10 A. D. Kennedy