I am trying to do this integral
\int_{-\infty}^{\infty}\frac{e^{-a| \vec{r}|}e^{-\vec{b}. \vec{r}}}{|\vec{r}|}
But if I write the modulus as
\vec{r}=\sqrt{x^{2}+y^{2}+z^{2}}
I can't figure out how to handle the annoying square root in the exponential.
Would be grateful for hints, thanks...