Comment on "Role of heavy meson exchange in near threshold NN-->d pi "

Abstract

In a recent paper by Horowitz [Phys. Rev. C 48, 2920 (1993)] a heavy meson exchange is incorporated into threshold NN\ensuremath{\rightarrow}d\ensuremath{\pi} to enhance the underestimated cross section. However, that calculation uses an unjustified assumption on the initial and final momenta, which causes an overestimate of this effect by a factor of 3--4. Further, I point out that the inclusion of the \ensuremath{\Delta}(1232) isobar increases the cross section significantly even at threshold. \textcopyright{} 1996 The American Physical Society.