  From the operator product expansion the gluon condensate controls a certain
power law correction to the ultraviolet behavior of the gauge theory. This is
reflected by the asymptotic behavior of the effective gluon mass function as
determined by its Schwinger-Dyson equation. We show that the current state of
the art determination of the gluon mass function by Binosi, Ibanez and
Papavassiliou points to a vanishing gluon condensate. If this is correct then
the vacuum energy also vanishes in massless QCD. This result can be interpreted
as a statement about a softness in the ultraviolet behavior and the consistency
of this behavior with a mass gap.
