= Scaleless integral
{title2=$\int d^dk\,(k^2)^{-a}=0$}
A <Feynman integral> with no nonzero <mass> or external <momentum> scale is assigned zero by <dimensional regularization>. This does not imply separate absence of <ultraviolet divergences> and <infrared divergences>. For a logarithmically scaleless example, zero can encode cancellation of the two pole contributions. Keeping a scale or using <auxiliary-mass extraction of ultraviolet poles> is necessary when only the ultraviolet part is sought.
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