Charge dependence of $NN\to d\pi$

Abstract

We calculate the isospin symmetry violating effects to the reactions $pp\rightarrow d\pi ^+$ and $np\rightarrow d\pi ^0$ arising from the different hadron masses and from the Coulomb interaction between the positive pion and the deuteron. These effects are large enough in the cross section and analyzing power $A_y$ that they should be taken into account in comparisons of accurate experiments in different charge channels.