  We study the zero frequency noise in an interacting quantum wire connected to
leads, in the presence of an impurity. In the absence of quasiparticle
decoherence the zero-frequency noise is that of a non-interacting wire.
However, if the collective, fractionally-charged modes have a finite lifetime,
we find that the zero-frequency noise may still exhibit signatures of charge
fractionalization, such as a small but detectable reduction of the ratio
between the noise and the backscattered current (Fano factor). We argue that
this small reduction of the Fano factor is consistent with recent observations
of a large reduction in the experimentally-inferred Fano factor in nanotubes
(calculated assuming that the backscattered current is the difference between
the ideal current in a multiple-channel non-interacting wire and the measured
current.
