  We study the unpolarized gluon quasidistribution function in the nucleon at
one loop level in the large momentum effective theory. For the quark
quasidistribution, power law ultraviolet divergences arise in the cut-off
scheme and an important observation is that they all are subjected to Wilson
lines. However for the gluon quasidistribution function, we first point out
that the linear ultraviolet divergences also exist in the real diagram which is
not connected to any Wilson line. We then study the one loop corrections to
parton distribution functions in both cut-off scheme and dimensional
regularization to deal with the ultraviolet divergences. In addition to the
ordinary quark and gluon distributions, we also include the quark to gluon and
gluon to quark splitting diagrams. The complete one-loop matching factors
between the quasi and light cone parton distribution functions are presented in
the cut-off scheme. We derive the $P^z$ evolution equation for quasi parton
distribution functions, and find that the $P^z$ evolution kernels are identical
to the DGLAP evolution kernels.

High Energy Physics - Phenomenology;High Energy Physics - Experiment;High Energy Physics - Lattice;Nuclear Theory