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Related papers: Cutoff effects of the gradient flow for fermions

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Effects of dynamical quarks on the microscopic spectrum of the Wilson Dirac operator are analyzed by means of effective field theory. We consider the distributions of the real modes of the Wilson Dirac operator as well as the spectrum of…

High Energy Physics - Lattice · Physics 2011-07-15 G. Akemann , P. H. Damgaard , K. Splittorff , J. J. M. Verbaarschot

Magnetic flux plays an important role in compactifications of field and string theories in two ways, it generates a multiplicity of chiral fermion zero modes and it can break supersymmetry. We derive the complete four-dimensional effective…

High Energy Physics - Theory · Physics 2017-04-26 Wilfried Buchmuller , Markus Dierigl , Emilian Dudas , Julian Schweizer

We present the first numerical investigation of the method proposed in Ref. [1] to utilize gradient flow to obtain precise determinations of higher moments of PDFs from lattice QCD, circumventing power divergent mixing with lower…

Three-flavor QCD simulation with the $O(a)$-improved Wilson fermion action is made employing an exact fermion algorithm developed for odd number of quark flavors. For the plaquette gauge action, an unexpected first-order phase transition is…

We consider Fermions in a constant and uniform external $SU(2)$ magnetic field. We find that the results for the energy levels depend on the choice of gauge potential. Choosing a Landau type gauge potential yields his results. On the other…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. H. Friedman , Y. Srivastava , A. Widom

We present results for the renormalization of gauge invariant nonlocal fermion operators which contain a Wilson line, to one loop level in lattice perturbation theory. Our calculations have been performed for Wilson/clover fermions and a…

High Energy Physics - Lattice · Physics 2018-04-18 M. Constantinou , H. Panagopoulos

Algorithms based on normalizing flows are emerging as promising machine learning approaches to sampling complicated probability distributions in a way that can be made asymptotically exact. In the context of lattice field theory,…

We consider the vacuum partition function of a 4d scalar QFT in a curved background as function of bare marginal and relevant couplings. A local UV cutoff $\Lambda(x)$ transforming under Weyl rescalings allows to construct Weyl invariant…

High Energy Physics - Theory · Physics 2022-01-19 Ulrich Ellwanger

We report on salient features of a mixed lattice QCD action using valence M\"{o}bius domain-wall fermions solved on the dynamical $N_f=2+1+1$ HISQ ensembles generated by the MILC Collaboration. The approximate chiral symmetry properties of…

The Schr\"odinger Functional (quantum/lattice field theory with Dirichlet boundary conditions) is a powerful tool in the non-perturbative improvement and for the study of other aspects of lattice QCD. Here we adapt it to improved gluon and…

High Energy Physics - Lattice · Physics 2009-10-30 T. R. Klassen

When analyzed in terms of the Symanzik expansion, lattice correlators of multi-local (gauge-invariant) operators with non-trivial continuum limit exhibit in maximally twisted lattice QCD ``infrared divergent'' cutoff effects of the type…

High Energy Physics - Lattice · Physics 2009-11-11 R. Frezzotti , G. Martinelli , M. Papinutto , G. C. Rossi

We construct chiral perturbation theory for the gradient flow of the microscopic Dirac eigenvalues and compute the density of and correlations between the microscopic eigenvalues at zero and non-zero flow time. The results show that the…

High Energy Physics - Lattice · Physics 2015-06-22 Alexander S. Christensen , K. Splittorff , J. J. M. Verbaarschot

The maximally twisted lattice QCD action of an $SU_f(2)$ doublet of mass degenerate Wilson quarks gives rise to a real positive fermion determinant and it is invariant under the product of standard parity times the change of sign of the…

High Energy Physics - Lattice · Physics 2009-11-10 R. Frezzotti , G. C. Rossi

We determine two improvement coefficients which are relevant to cancel mass-dependent cutoff effects in correlation functions with operator insertions of the non-singlet local QCD vector current. This determination is based on degenerate…

High Energy Physics - Lattice · Physics 2018-06-07 Patrick Fritzsch

We study the convergence of the derivative expansion for flow equations. The convergence strongly depends on the choice for the infrared regularisation. Based on the structure of the flow, we explain why optimised regulators lead to better…

High Energy Physics - Theory · Physics 2009-11-07 Daniel F. Litim

We investigate a new class of improved relativistic fermion action on the lattice with a criterion to give excellent energy-momentum dispersion relation as well as to be consistent with tree-level $O\left(a^{2}\right)$-improvement. Main…

High Energy Physics - Lattice · Physics 2013-12-18 Yong-Gwi Cho , Shoji Hashimoto , Jun-Ichi Noaki , Andreas Jüttner , Marina Marinkovic

We calculate the renormalized step scaling function for twelve fundamental flavors nonperturbatively by determining the gradient flow coupling on gauge field configurations generated with dynamical stout-smeared M\"obius domain wall…

High Energy Physics - Lattice · Physics 2018-10-15 Anna Hasenfratz , Claudio Rebbi , Oliver Witzel

The gradient (Wilson) flow has been introduced recently in order to provide a solid theoretical framework for the smoothing of ultraviolet noise in lattice gauge configurations. It is interesting to ask how it compares with other, more…

High Energy Physics - Lattice · Physics 2014-05-14 Claudio Bonati , Massimo D'Elia

We determine non-perturbatively the normalisation constant Z_m*Z_P/Z_A as well as the Symanzik coefficients b_m and b_A-b_P, required in O(a) improved quark mass renormalisation with Wilson fermions. The strategy underlying their…

We present our first set of results for charm physics, using the mixed-action setup introduced in a companion paper. Maximally twisted Wilson valence fermions are used on a sea of non-perturbatively $O(a)$-improved Wilson fermions, made up…