English
Related papers

Related papers: Lattice QCD without tuning, mixing and current ren…

200 papers

It is shown how on-shell O(a) improvement can be implemented non-perturbatively in lattice QCD with Wilson quarks. Improvement conditions are obtained by requiring the PCAC relation to hold exactly in certain matrix elements. These are…

High Energy Physics - Lattice · Physics 2009-10-28 M. Lüscher , S. Sint , R. Sommer , P. Weisz , H. Wittig , U. Wolff

We report on our calculation of the kaon semileptonic form factors in Nf=2+1 lattice QCD. Chiral symmetry is exactly preserved by using the overlap quark action for a straightforward comparison with chiral perturbation theory (ChPT). We…

High Energy Physics - Lattice · Physics 2011-12-23 JLQCD Collaboration , T. Kaneko , S. Aoki , G. Cossu , X. Feng , H. Fukaya , S. Hashimoto , J. Noaki , T. Onogi

I report on the current status of QCD phase diagram at vanishing baryon density. I focus on the QCD phase diagram with three degenerate quark flavor using Highly Improved Staggered Quarks on $N_{\tau}=6$ lattices. No evidence of a first…

High Energy Physics - Lattice · Physics 2015-06-15 Heng-Tong Ding

While chiral symmetry breaking in the QCD vacuum is attributed to nonzero chiral condensate, an alternative symmetry breaking pattern with no chiral condensate is also possible, as pointed out by Stern. This hypothetical phase was excluded…

High Energy Physics - Phenomenology · Physics 2015-10-06 Takuya Kanazawa

We have simulated lattice QCD directly in the chiral limit of zero quark mass by adding an additional, irrelevant 4-fermion interaction to the standard action. Using lattices having temporal extent of six and spatial extents of twelve and…

High Energy Physics - Lattice · Physics 2009-10-31 J. B. Kogut , D. K. Sinclair

The Vafa-Witten arguments on the realization of parity and flavour symmetries in the QCD vacuum do not apply to two lattice regularizations of QCD which are able to reproduce the chiral anomaly: Wilson fermions and Ginsparg-Wilson fermions.…

High Energy Physics - Lattice · Physics 2010-11-04 V. Azcoiti , G. Di Carlo , E. Follana , A. Vaquero

A general strategy to solve the non-perturbative renormalization problem in lattice QCD, using finite-size techniques and numerical simulations, is described. As an illustration we discuss the computation of the axial current normalization…

High Energy Physics - Lattice · Physics 2009-10-28 Karl Jansen , Chuan Liu , Martin Luescher , Hubert Simma , Stefan Sint , Rainer Sommer , Peter Weisz , Ulli Wolff

We study the pion velocity at the critical temperature of chiral symmetry restoration in QCD. Starting from the premise that the bare effective field theory is to be defined from the underlying QCD, we incorporate the effects of Lorentz…

High Energy Physics - Phenomenology · Physics 2009-11-10 Chihiro Sasaki

Based upon the lattice Dirac operator satisfying the Ginsparg-Wilson relation, we investigate canonical formulation of massless fermion on the spatial lattice. For free fermion system exact chiral symmetry can be implemented without species…

High Energy Physics - Lattice · Physics 2009-11-11 Kosuke Matsui , Tomohiro Okamoto , Takanori Fujiwara

At sufficiently high temperature and density, quantum chromodynamics (QCD) is expected to undergo a phase transition from the confined phase to the quark-gluon plasma phase. In the Lagrangian lattice formulation the Monte Carlo method works…

High Energy Physics - Lattice · Physics 2009-10-31 E. B. Gregory , S. Guo , H. Kroger , Xiang-Qian Luo

One of the most challenging issues in QCD is the investigation of spontaneous chiral-symmetry breaking, which is characterized by the non-vanishing chiral condensate when the bare fermion mass is zero. In standard methods, one has to…

High Energy Physics - Lattice · Physics 2007-05-23 Xiang-Qian Luo

We use perturbation theory to construct perfect lattice actions for fermions and gauge fields by blocking directly from the continuum. When one uses a renormalization group transformation that preserves chiral symmetry the resulting lattice…

High Energy Physics - Lattice · Physics 2009-10-28 W. Bietenholz , U. -J. Wiese

We use the effective chiral Lagrangian to analyze the phase diagram of two-flavor twisted mass lattice QCD as a function of the normal and twisted masses, generalizing previous work for the untwisted theory. We first determine the chiral…

High Energy Physics - Lattice · Physics 2009-11-10 Stephen R. Sharpe , Jackson M. S. Wu

Using functional techniques, we prove, to all orders of perturbation theory, that lattice vector gauge theories with Ginsparg Wilson fermions are renormalizable. For two or more massless fermions, they satisfy a flavour mixing axial vector…

High Energy Physics - Lattice · Physics 2009-10-31 T. Reisz , H. J. Rothe

We show that lattice results on four flavor QCD at nonzero temperature and baryon density compare well with the hadron resonance gas model up to T approx. 0.95 Tc, and approach a free field behaviour with a reduced effective number of…

High Energy Physics - Lattice · Physics 2017-08-23 M. D'Elia , M. P. Lombardo

The main ideas behind the new ways to preserve chiral symmetries for lattice fermions are presented. The discussion is focused on vector-like fermions, the case relevant for lattice QCD.

High Energy Physics - Lattice · Physics 2007-05-23 Herbert Neuberger

We determine the phase diagram and chiral condensate for lattice QCD with two flavors of twisted-mass fermions in the presence of nondegenerate up and down quarks, discretization errors and a nonzero value of $\Theta_{\rm QCD}$. Although…

High Energy Physics - Lattice · Physics 2015-11-25 Derek P. Horkel , Stephen R. Sharpe

Dynamical chiral-symmetry breaking in QCD is studied with the Schwinger-Dyson (SD) formalism based on lattice QCD data, i.e., LQCD-based SD formalism. We extract the SD kernel function $K(p^2)$ in an Ansatz-independent manner from the…

High Energy Physics - Phenomenology · Physics 2009-11-10 Hideaki Iida , Makoto Oka , Hideo Suganuma

We report a proof-of-principle lattice QCD simulation of the electric and magnetic polarizabilities for a neutral pion in the four-point function method. The results are based on the same quenched Wilson ensembles on a $24^3\times 48$…

High Energy Physics - Lattice · Physics 2024-10-11 Frank X. Lee , Walter Wilcox , Andrei Alexandru , Chris Culver , Shayan Nadeem

Quantum chromodynamics (QCD) at sufficiently high density is expected to undergo a chiral phase transition. Understanding such a transition is of particular importance for neutron star or quark star physics. In Lagrangian SU(3) lattice…

High Energy Physics - Lattice · Physics 2009-11-07 Yi-Zhong Fang , Xiang-Qian Luo