  We describe methods for evaluating one-loop integrals in $4-2\e$ dimensions.
We give a recursion relation that expresses the scalar $n$-point integral as a
cyclicly symmetric combination of $(n-1)$-point integrals. The computation of
such integrals thus reduces to the calculation of box diagrams ($n=4$). The
tensor integrals required in gauge theory may be obtained by differentiating
the scalar integral with respect to certain combinations of the kinematic
variables. Such relations also lead to differential equations for scalar
integrals. For box integrals with massless internal lines these differential
equations are easy to solve.

High Energy Physics - Phenomenology;High Energy Physics - Theory