Chiral Symmetry and O(a) Improvement in Lattice Qcd
نویسندگان
چکیده
The dominant cutoo eeects in lattice QCD with Wilson quarks are proportional to the lattice spacing a. In particular, the isovector axial current satisses the PCAC relation only up to such eeects. Following a suggestion of Symanzik, they can be cancelled by adding local O(a) correction terms to the action and the axial current. We here address a number of theoretical issues in connection with the O(a) improvement of lattice QCD and then show that chiral symmetry can be used to x the coeecients multiplying the correction terms.
منابع مشابه
Lattice Qcd with a Chiral Twist *
In these lectures I explain how chiral symmetry of continuum QCD naturally leads to a class of lattice regularisations known as twisted mass QCD (tmQCD). As compared to standard Wilson quarks, its advantages are the absence of unphysi-cal zero modes, the possibility to circumvent lattice renormalisation problems and automatic O(a) improvement. On the other hand, the physical parity and flavour ...
متن کاملNon-perturbative Renormalization in Lattice Field Theory *
I review the strategies which have been developped in recent years to solve the non-perturbative renormalization problem in lattice field theories. Although the techniques are general, the focus will be on applications to lattice QCD. I discuss the momentum subtraction and finite volume schemes, and their application to scale dependent renormalizations. The problem of finite renormalizations is...
متن کاملChiral symmetry and lattice QCD
Four lectures about chiral symmetry and dynamical fermions in QCD. 1) Chiral symmetry in continuum QCD with an eye toward lattice simulations. 2) Lattice fermions with exact chiral symmetry: staggered fermions, fermions in five dimensions, chiral fermions in four dimensions. 3) A typical lattice simulation from beginning to end: the simulation algorithm, designing observables to measure some de...
متن کاملChiral Symmetry on the Lattice
As a non-perturbative and gauge invariant regularization the lattice provides a tool for deeper understanding of the celebrated Yang-Mills theory, QCD and chiral gauge theories. For illustration, I discuss some analytic developments on the lattice related to chiral symmetry, chiral fermions and improvement programs. Chiral symmetry on the lattice has an amazing history, and it might influence o...
متن کاملar X iv : h ep - l at / 0 40 60 33 v 1 1 9 Ju n 20 04 Chiral symmetry on the lattice
As a non-perturbative and gauge invariant regularization the lattice provides a tool for deeper understanding of the celebrated Yang-Mills theory, QCD and chiral gauge theories. For illustration, I discuss some analytic developments on the lattice related to chiral symmetry, chiral fermions and improvement programs. Chiral symmetry on the lattice has an amazing history, and it might influence o...
متن کامل