  In this paper, we present a new approach to the Kratky-Porod Model (KP) of
semiflexible polymers. Our solution to the model is based on the definition of
a generating function which we use to study the statistical mechanics of
semiflexible polymer chains. Specifically, we derive mathematical expressions
for the characteristic function, the polymer propagator and the mean square
end-to-end distance from the generating function. These expressions are valid
for polymers with any number of segments and degree of rigidity. Furthermore,
they capture the limits of fully flexible and stiff polymers exactly. In
between, a smooth and approximate crossover behavior is predicted. The most
important contribution of this paper is the expression of the polymer
propagator which is written in a very simple and insightful way. It is given in
terms of the exact polymer propagator of the Random Flight Model multiplied by
an exponential that takes into account the stiffness of the polymer backbone.
