  Using methods of effective field theory, we show that after resummation of
Sudakov logarithms the spectral densities of interacting quark and gluon fields
in ordinary quantum field theories such as QCD are virtually indistinguishable
from those of "unparticles" of a hypothetical conformal sector coupled to the
Standard Model, recently studied by Georgi. Unparticles are therefore less
exotic that originally thought. Models in which a hidden sector weakly coupled
to the Standard Model contains a QCD-like theory, which confines at some scale
much below the characteristic energy of a given process, can give rise to
signatures closely resembling those from unparticles.
