Total cross sections and analyzing powers for the reactionp+p→p+p+π0near threshold

We have studied the reaction p+p→p+p+${\mathrm{\pi }}^0$ from 320 to 500 MeV by detecting the γ rays from ${\mathrm{\pi }}^0$ decay in coincidence in two large NaI crystals. The obtained differential and total cross sections of the pions are in agreement with previous measurements but are of a higher precision. We have also measured the pion analyzing powers; the first measurement of this observable. Our results are compared with those for the reactions np→NN${\mathrm{\pi }}^{\pm }$ with confusing conclusions concerning the contribution of ${\mathrm{\sigma }}_{01}$, the zero isospin pion production channel.