arXiv subjects

Achim Bode

Publications and source records attributed to Achim Bode.

4 recordsLinked to original sources

arXiv2001

First results on the running coupling in QCD with two massless flavours

We report on the non-perturbative computation of the running coupling of two-flavour QCD in the Schr"odinger functional scheme. The corresponding Lambda-parameter, which describes the coupling strength at high energy, is related to a low energy scale which still remains to be connected to a hadronic ``experimentally'' observable quantity. We find the non-perturbative evolution of the coupling indispensable to avoid untolerable errors in the estimated Lambda-parameter.

hep-lat↗

arXiv2001

Two Loop Computation of the Schroedinger Functional in Lattice QCD

We compute the Schroedinger functional (SF) for the case of lattice QCD with Wilson fermions (with and without SW improvement) at two-loop order in lattice perturbation theory. This allows us to extract the three-loop beta-function in the SF-scheme. These results are required to compute the running coupling, the Lambda-parameter and quark masses by finite size techniques with negligible systematic errors. In addition our results enable the implementation of two-loop O(a) improvement in SF-simulations.

hep-lat↗

arXiv1999

First experiences with HMC for dynamical overlap fermions

We describe an HMC algorithm for dynamical overlap fermions which makes use of their good chiral properties. We test the algorithm in the Schwinger model. Topological sectors are readily changed even in the massless case.

hep-lat↗

arXiv1997

Two loop expansion of the Schroedinger functional coupling alpha_SF in SU(3) lattice gauge theory

The two loop coefficient of the expansion of the Schroedinger functional coupling in terms of the lattice coupling is calculated for the SU(3) Yang-Mills theory. This coefficient is required to relate lattice data to the MS-bar-coupling. As a byproduct of the calculation, the Schroedinger functional is improved to two loop order and the three loop coefficient of the beta function in the SF-scheme is derived.

hep-lat↗