The old and the new of parity-violating two-pion-exchange $NN$ potential

Abstract

We consider the parity-violating two-pion-exchange potential obtained from the covariant formalism in the past and the state-of-the-art effective field theory approach. We discuss the behavior of the potential in coordinate space and its application to the parity-violating asymmetry in $\vec{n} p \to d \gamma$ at threshold.