  We have investigated shot noise in graphene field effect devices in the
temperature range of 4.2--30 K at low frequency ($f$ = 600--850 MHz). We find
that for our graphene samples with large width over length ratio $W/L$, the
Fano factor $\mathfrak{F}$ reaches a maximum $\mathfrak{F} \sim$ 1/3 at the
Dirac point and that it decreases strongly with increasing charge density. For
smaller $W/L$, the Fano factor at Dirac point is significantly lower. Our
results are in good agreement with the theory describing that transport at the
Dirac point in clean graphene arises from evanescent electronic states.
