Quark-gluon vertex with an off-shell O(a)-improved chiral fermion action

Abstract

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 both with the non-perturbatively improved clover coefficient as well as with a number of different values for this coefficient. We find that the domain wall vertex function behaves very well in the large momentum transfer region. The off-shell vertex function for the on-shell improved clover class of actions does not behave as well as the domain wall case and, surprisingly, shows only a weak dependence on the clover coefficient $c_{SW}$ for all components of its Dirac decomposition and across all momenta. Including off-shell improvement rotations for the clover fields can make this action yield results consistent with those from the domain wall approach, as well as helping to determine the off-shell improved coefficient $c_q^{\prime }$.

11 pages, 13 figures, REVTeX 4

References in corpus (3)

• Unquenched Gluon Propagator in Landau Gauge
• Quark-gluon vertex in arbitrary kinematics
• Non-perturbative determination of heavy quark action coefficients

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• Stout-link smearing in lattice fermion actions
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