Charge independence studied in $NN\to d\pi$ reactions

Abstract

We review to what extent charge independence breaking (\emph{CIB}) in isospin related reactions of the type $NN\to d\pi$ can or could be seen in existing data. In doing this we present fits to global and threshold cross sections including most recent data. Applying these we point out the probable impossibility to make model independent predictions even based solely on the different threshold energies and the well known $pp\to d\pi^+$. A possible discrepancy is seen between the $np\to d\pi^0$ and $pp\to d\pi^+$ data, which may require invoking explicitly isospin symmetry breaking interactions.