2,013 research outputs found
Code Usage Analysis System (CUAS)
A set of computer programs is offered to aid a user in evaluating performance of an application program. The system provides reports of subroutine usage, program errors, and segment loading which occurred during the execution of an application program. It is presented in support of the development and validation of the space vehicle dynamics project
One-loop renormalisation for the second moment of GPDs with Wilson fermions
We calculate the non-forward quark matrix elements for operators with two
covariant derivatives in one-loop lattice perturbation theory using Wilson
fermions. These matrix elements are needed in the renormalisation of the second
moment of generalised parton distributions measured in lattice QCD. For some
commonly used representations of the hypercubic group we determine the sets of
all mixing operators and find the matrices of mixing and renormalisation
factors.Comment: Lattice 2004(improved), 3 pages, LaTeX style file, espcrc2.sty
include
Renormalisation of one-link quark operators for overlap fermions with L\"uscher-Weisz gauge action
We compute lattice renormalisation constants of one-link quark operators
({\it i.e.} operators with one covariant derivative) for overlap fermions and
L\"uscher-Weisz gauge action in one-loop perturbation theory. Among others,
such operators enter the calculation of moments of polarised and unpolarised
hadron structure functions. Results are given for \beta=8.45, \beta=8.0 and
mass parameter \rho=1.4, which are commonly used in numerical simulations. We
apply mean field (tadpole) improvement to our results.Comment: 13 pages, 1 figur
Perturbative renormalisation of quark bilinear operators for overlap fermions with and without stout links and improved gauge action
We calculate lattice renormalisation constants of local and one-link quark
operators for overlap fermions and improved gauge actions in one-loop
perturbation theory. For the local operators we stout smear the SU(3) links in
the fermionic action. Using the popular tadpole improved L\"uscher-Weisz
actions at and we present numerical values for the Z
factors in the scheme (partly as function of the stout smearing
strength). We compare various levels of mean field (tadpole) improvement which
have been applied to our results.Comment: 7 page
The SU(3) Beta Function from Numerical Stochastic Perturbation Theory
The SU(3) beta function is computed from Wilson loops to 20th order numerical
stochastic perturbation theory. An attempt is made to include massless
fermions, whose contribution is known analytically to 4th order. The question
whether the theory admits an infrared stable fixed point is addressed.Comment: 10 pages, 7 figures, version to be published in Physics Letters
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