Integration Over Feynman Parameters Arising from an Expectation of a Rational Function – mathoverflow.net

Let $\mathbf a,\mathbf b\in\mathbb R^{n}$ be generic vectors, and $(s,t)\in\left[0,1\right]^2$. Define $$ A=|\mathbf a-\mathbf b|^{2},\qquad B(s)=|s\mathbf a+(1-s)\mathbf b|^{2},\qquad C=\sqrt{\|\...