In a recent paper by Horowitz [Phys. Rev. C 48, 2920 (1993)] a heavy meson exchange is incorporated into threshold NN→dπ 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 Δ(1232) isobar increases the cross section significantly even at threshold. © 1996 The American Physical Society.

• Received 18 January 1995

DOI:https://doi.org/10.1103/PhysRevC.53.526