  The influence of the underlying nucleon-nucleon collision geometry on
evaluations of the nuclear overlap function ($T_{AB}$) and number of binary
collisions ($N_{coll}$) is studied. A narrowing of the spatial distribution of
the hard-partons with large light-cone fraction $x$ in nucleons leads to a
downward correction for $N_{coll}$ and $T_{AB}$, which in turn, results in an
upward correction for the nuclear modification factor $R_{AB}$. The size of
this correction is estimated for several experimentally motivated
nucleon-nucleon overlap functions for hard-partons. It is found to be
significant in peripheral nucleus-nucleus and nucleon-nucleus collisions, and
are much larger at the LHC energy of $\sqrt{s}=5.5$ TeV than for the RHIC
energy of $\sqrt{s}$=200 GeV. The implications for experimental measurements
are also discussed.
