Phenomenological consequences of the infrared singular, instantaneous part of
the gluon propagator in Coulomb gauge are investigated. The corresponding quark
Dyson-Schwinger equation is solved, neglecting retardation and transverse
gluons and regulating the resulting infrared singularities. While the quark
propagator vanishes as the infrared regulator goes to zero, the frequency
integral over the quark propagator stays finite and well-defined. Solutions of
the homogeneous Bethe-Salpeter equation for the pseudoscalar and vector mesons
as well as for scalar and axial-vector diquarks are obtained. In the limit of a
vanishing infrared regulator the diquark masses diverge, while meson properties
and diquark radii remain finite and well-defined. These features are
interpreted with respect to the resulting aspects of confinement for colored
quark-quark correlations.Comment: 4 pages, 6 figure