Production and Absorption ofS-Wave Pions at Low Energy by Two Nucleons

The cross sections for the reactions $p+p\to d+{\pi }^{+}$ and $p+p\to p+p+{\pi }^0$ are calculated for $s$-wave pions at threshold. The pion is produced by either nucleon and emitted directly or rescattered in an $s$ wave by the second nucleon, through a modified static interaction. The two nucleons interact through a phenomenological potential. For the Hamada-Johnston potential both calculated cross sections agree with experimental results. Application of the method of calculation to the nuclear absorption of $s$-wave pions is discussed.