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Related papers: Chiral Ward identities, automatic O(a) improvement…

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Chiral properties of QCD formulated with the domain-wall fermion (DWQCD) are studied using the anomalous quark mass m_{5q} and the spectrum of the 4-dimensional Wilson-Dirac operator. Numerical simulations are made with the standard…

The Schroedinger functional provides a valuable tool to perform non-perturbative renormalization on the lattice, in particular in a mass independent scheme. We study two different types of chirally rotated Schroedinger functional boundary…

High Energy Physics - Lattice · Physics 2009-04-14 J. Gonzalez Lopez , K. Jansen , A. Shindler

Flavor singlet and non-singlet axial Ward identities are investigated using the Wilson formulation of lattice QCD with Clover O(a)-improvement, which breaks explicitly chiral symmetry. The matching at one-loop order of all the relevant…

High Energy Physics - Lattice · Physics 2015-06-25 D. Guadagnoli , S. Simula

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 gradient flow is the evolution of fields and physical quantities along a dimensionful parameter~$t$, the flow time. We give a simple argument that relates this gradient flow and the Wilsonian renormalization group (RG) flow. We then…

High Energy Physics - Theory · Physics 2021-07-09 Hiroki Makino , Okuto Morikawa , Hiroshi Suzuki

We consider a Wilson-Dirac operator with improved chiral properties. We show that, for arbitrarily rough gauge fields, it satisfies the index theorem if we identify the zero modes with the small real eigenvalues of the fermion operator and…

High Energy Physics - Lattice · Physics 2009-10-31 P. Hernandez

The gradient flow exponentially suppresses ultraviolet field fluctuations and removes ultraviolet divergences (up to a multiplicative fermionic wavefunction renormalization). It can be used to describe real-space Wilsonian renormalization…

High Energy Physics - Lattice · Physics 2022-02-21 Anna Hasenfratz , Christopher J. Monahan , Matthew D. Rizik , Andrea Shindler , Oliver Witzel

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 2009-10-31 Thomas DeGrand , Anna Hasenfratz , Tamas G. Kovacs

We present results for the renormalisation constants of bilinear quark operators, using the Nf=2 twisted mass Wilson action at maximal twist (which guarantees automatic O(a) improvement) and the tree-level Symanzik improved gauge action.…

High Energy Physics - Lattice · Physics 2009-04-14 P. Dimopoulos , R. Frezzotti , G. Herdoiza , V. Lubicz , M. Papinutto , S. Simula , A. Vladikas

A completely non-perturbative estimate is given for gA using both quenched and unquenched O(a) improved Wilson fermions. Particular attention is paid to the determination of the axial renormalisation constant, ZA, using the Ward identity…

High Energy Physics - Lattice · Physics 2009-10-31 R. Horsley

A non-perturbative determination of the axial current improvement coefficient cA is performed with two flavors of dynamical improved Wilson fermions and plaquette gauge action. The improvement condition is formulated with Schroedinger…

High Energy Physics - Lattice · Physics 2008-11-26 Michele Della Morte , Roland Hoffmann , Rainer Sommer

We compare the behavior of overlap fermions, which are chirally invariant, and of Wilson twisted mass fermions at full twist in the approach to the chiral limit. Our quenched simulations reveal that with both formulations of lattice…

Up until now, the BCFW technique has been a widely used method in getting the amplitudes in various theories. Usually, the vanishing of the boundary term is necessary for the efficiency of the method. However, there are also many kinds of…

High Energy Physics - Theory · Physics 2012-04-06 Gang Chen

The functional flow equation and the Quantum Master equation are consistently solved in perturbation for the chiral symmetric QED with and without four-fermi interactions. Due to the presence of momentum cutoff, unconventional features…

High Energy Physics - Theory · Physics 2021-07-30 Yuji Igarashi , Katsumi Itoh

Normality of the Dirac operator is shown to be necessary for chiral properties. From the global chiral Ward identity, which in the continuum limit gives the index theorem, a sum rule results which constrains the spectrum. The…

High Energy Physics - Lattice · Physics 2011-04-15 Werner Kerler

We define an index of the fermionic signature operator on even-dimensional globally hyperbolic spin manifolds of finite lifetime. The invariance of the index under homotopies is studied. The definition is generalized to causal fermion…

Mathematical Physics · Physics 2017-06-12 Felix Finster

We derive Ward identities for fermionic systems exhibiting a gauge symmetry that gets globally broken. In particular, we focus on the relation that connects the gauge field response functions to the transverse susceptibilities of the order…

Strongly Correlated Electrons · Physics 2024-08-08 Pietro M. Bonetti

We investigate chiral properties of the domain-wall fermion (DWF) system. After a brief introduction for the DWF, we summarize the recent numerical results on the chiral properties of the domain-wall QCD (DWQCD), which seem mutually…

High Energy Physics - Lattice · Physics 2009-11-07 Sinya Aoki

We perform a study the quark-gluon vertex function with a quenched Wilson gauge action and a variety of fermion actions. These include the domain wall fermion action (with exponentially accurate chiral symmetry) and the Wilson clover action…

High Energy Physics - Lattice · Physics 2009-11-11 Huey-Wen Lin

It is emphasized that for interactions with derivative couplings, the Ward Identity (WI) securing the preservation of a global U(1) symmetry should be modified. Scalar QED is taken as an explicit example. More precisely, it is rigorously…

Mathematical Physics · Physics 2021-04-01 Michael Dütsch , Luis Peters , Karl-Henning Rehren