 Ultraviolet pole of QED fermion self-energy

In Feynman gauge, with insertion $-i\Sigma (p)$ and $d=4-2ϵ$, the one-loop QED result is ${\Sigma }_{\mathrm{UV}}=e^2(-/p+4m)/(16{\pi }^2ϵ)$. The coefficient of $/p$ is the electron kinetic counterterm ${\delta }_2=-e^2/(16{\pi }^2ϵ)$ when its insertion is $i/p{\delta }_2$. The scalar part fixes a separate mass counterterm in the chosen normalization convention.