Recent content by sbh77

ah, my mistake, x and r are the same thing. I am just comparing the first Born approximation with that of the transition matrix element for two fermions scattering off of each other. By making this comparison it can be seen that the potential (in momentum space) is V(q) = \frac{-g^2}{q^2+m^2}...

Homework Statement V(x) = \int \frac{d^3q}{(2\pi)^3} \frac{-g^2}{|\vec{q}|^2 + m^2} \exp^{i \vec{q} \cdot \vec{x}} = -\frac{g^2}{4\pi^2} \int_0^{\infty} dq q^2 \frac{exp^{iqr}-exp^{-iqr}}{iqr} \frac{1}{q^2+m^2} = \frac{-g^2}{4\pi^2 i r} \int_{-\infty}^{\infty} dq \frac{q...

Hi all, This might be simple but I haven't figured out a way to do this. Basically I have the result in coordinate space and 3+1 spacedimensions, to order lambda^2, \frac{(-i \lambda)^2}{2!} \int dx dy (i D_F(x-y))^2 (i D_F(x1-x)) (i D_F(x2-x)) (i D_F(x3-y)) (i D_F(x4-x))...