Wino potential and Sommerfeld effect at NLO

We calculate the SU(2)$\times$U(1) electroweak static potential between a fermionic triplet in the broken phase of the Standard Model in the one-loop order (NLO). The one-loop correction provides the leading non-relativistic correction to the large Sommerfeld effect in the annihilation of wino or wino-like dark matter particles ${\chi }^0$. We find sizeable modifications of the ${\chi }^0{\chi }^0$ annihilation cross section and determine the shifts of the resonance locations due to the loop correction to the wino potential.