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Related papers: Why rooting fails

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The rooting procedure commonly used with staggered fermions does not correctly treat non-perturbative effects associated with gauge field topology. In practice these effects are small for the physics of flavor non-singlet particles. However…

High Energy Physics - Lattice · Physics 2009-06-25 Michael Creutz

In hep-lat/0701018, Creutz claims that the rooting trick used in simulations of staggered fermions to reduce the number of tastes misses key physics whenever the desired theory has an odd number of continuum flavors, and uses this argument…

High Energy Physics - Lattice · Physics 2008-11-26 Claude Bernard , Maarten Golterman , Yigal Shamir , Stephen Sharpe

To investigate the viability of the 4th root trick for the staggered fermion determinant in a simpler setting, we consider a two taste (flavor) lattice fermion formulation with no taste mixing but with exact taste-nonsinglet chiral…

High Energy Physics - Lattice · Physics 2008-11-26 David H. Adams

Staggered chiral perturbation theory (schpt) takes into account the "fourth-root trick" for reducing unwanted (taste) degrees of freedom with staggered quarks by multiplying the contribution of each sea quark loop by a factor of 1/4. In the…

High Energy Physics - Lattice · Physics 2009-11-11 C. Bernard

A recent criticism of the proof of the failure of the rooting procedure with staggered fermions is shown to be incorrect.

High Energy Physics - Lattice · Physics 2008-11-26 Michael Creutz

Even highly improved variants of lattice QCD with staggered fermions show significant violations of taste symmetry at currently accessible lattice spacings. In addition, the "rooting trick" is used in order to simulate with the correct…

High Energy Physics - Lattice · Physics 2008-11-26 Claude Bernard , Maarten Golterman , Yigal Shamir

With sufficiently light up and down quarks the isovector ($a_0$) and isosinglet ($f_0$) scalar meson propagators are dominated at large distance by two-meson states. In the staggered fermion formulation of lattice quantum chromodynamics,…

High Energy Physics - Lattice · Physics 2008-11-26 Claude Bernard , Carleton DeTar , Ziwen Fu , Sasa Prelovsek

Staggered fermions with 4 tastes are expected to describe 4-flavor QCD in the continuum limit, therefore at finite lattice spacing the staggered determinant should be equivalent to an SU(4) flavor-symmetric system up to lattice artifacts.…

High Energy Physics - Lattice · Physics 2007-05-23 Anna Hasenfratz

We present a completed random matrix theory for staggered fermions which incorporates all taste symmetry breaking terms at their leading order from the staggered chiral Lagrangian. This is an extension of previous work which only included…

High Energy Physics - Lattice · Physics 2012-04-26 James C. Osborn

A popular approximation in lattice gauge theory is an extrapolation in the number of fermion species away from the four fold degeneracy natural with the staggered fermion formulation. I show that the extrapolation procedure mutilates the…

High Energy Physics - Lattice · Physics 2008-11-26 Michael Creutz

We investigate the properties of staggered-fermion lattice QCD in which the fourth root of the fermion determinant is taken. We show that this theory is non-local at non-zero lattice spacing $a$, and that the non-locality is caused by the…

High Energy Physics - Lattice · Physics 2008-11-26 Claude Bernard , Maarten Golterman , Yigal Shamir

We discuss the construction of a chiral random matrix model for staggered fermions. This model includes $O(a^2)$ corrections to the continuum limit of staggered fermions and is related to the zero momentum limit of the Lee-Sharpe Lagrangian…

High Energy Physics - Lattice · Physics 2007-05-23 James C. Osborn

We compare the lower edge spectral fluctuations of the staggered lattice Dirac operator for the Schwinger model with the predictions of chiral Random Matrix Theory (chRMT). We verify their range of applicability, checking in particular the…

High Energy Physics - Lattice · Physics 2009-10-31 F. Farchioni , I. Hip , C. B. Lang

It is shown that the flavour projection of staggered fermions can be written as a projection between the fields on four separate, but parallel, lattices, where the fields on each are modified forms of the standard staggered fermion field.…

High Energy Physics - Lattice · Physics 2010-10-27 Steven Watterson

In this talk, I will give an overview of the theoretical status of staggered Lattice QCD with the "fourth-root trick." In this regularization of QCD, a separate staggered quark field is used for each physical flavor, and the inherent…

High Energy Physics - Phenomenology · Physics 2009-09-02 Maarten Golterman

I give a status report on the validity of the so-called ``fourth-root trick'', i.e. the procedure of representing the determinant for a single fermion by the fourth root of the staggered fermion determinant. This has been used by the MILC…

High Energy Physics - Lattice · Physics 2011-05-05 Stephen R. Sharpe

We study taste and Euclidean rotational symmetry violation for staggered fermions at nonzero lattice spacing using staggered chiral perturbation theory. We extend the staggered chiral Lagrangian to O(a^2 p^2), O(a^4) and O(a^2 m), the…

High Energy Physics - Lattice · Physics 2010-11-19 Stephen R. Sharpe , Ruth S. Van de Water

A popular approximation in lattice gauge theory is an extrapolation in the number of fermion species away from the four fold degeneracy natural with the staggered fermions formulation. I show that at finite lattice spacing and for an odd…

High Energy Physics - Lattice · Physics 2007-05-23 Michael Creutz

As one test of the validity of the staggered-fermion fourth-root determinant trick, we examine the suppression of the topological susceptibility of the QCD vacuum in the limit of small quark mass. The suppression is sensitive to the number…

High Energy Physics - Lattice · Physics 2008-11-26 C. Aubin , C. Bernard , Brian Billeter , C. DeTar , Steven Gottlieb , E. Gregory , U. M. Heller , J. E. Hetrick , J. Osborn , R. L. Sugar , D. Toussaint

We address the locality problem arising in simulations, which take the square root of the staggered fermion determinant as a Boltzmann weight to reduce the number of dynamical quark tastes from four to two. We study analytically and…

High Energy Physics - Lattice · Physics 2009-11-10 B. Bunk , M. Della Morte , K. Jansen , F. Knechtli
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