Dimensionally regularized one-loop tensor-integrals with massless   internal particles
  A set of one-loop vertex and box tensor-integrals with massless internal particles has been obtained directly without any reduction method to scalar-integrals. The results with one or two massive external lines for the vertex integral and zero or one massive external lines for the box integral are shown in this report. Dimensional regularization is employed to treat any soft and collinear (IR) divergence. A series expansion of tensor-integrals with respect to an extra space-time dimension for the dimensional regularization is also given. The results are expressed by very short formulas in a suitable manner for a numerical calculation. 
Y. Kurihara