We consider pair production and decay of fundamental unstable particles in
the framework of a modified perturbation theory treating resonant contributions
in the sense of distributions. Outcomes of a numerical simulation up to the
NNLO with taking into account universal massless-particles contributions are
presented.Comment: 3 pages, 1 figure, Talk given at 14th Lomonosov Conference on
Elementary Particle Physics, Moscow, August 19-25, 200