On the parameter space of Feynman integral and its applications

摘要

We show the several features of the parameter space in Feynman integral exponential parametrization. Using this parameter coordinate we can calculate Feynman integrals simply and elegantly, especially two-point loop and three-point vertex integrals. We try to calculate Γ(K_s~0→π~+π~-) using this differentiable manifold parameter coordinate.