Total cross section for p+d-->p+d+ pi 0 close to threshold.

Abstract

The total cross section for pion production in the reaction pd\ensuremath{\rightarrow}pd${\mathrm{\ensuremath{\pi}}}^{0}$ has been measured for bombarding energies from ${\mathit{T}}_{\mathit{p}}$=208.4 MeV to 294.6 MeV. This corresponds to maximum pion momenta \ensuremath{\eta}=${\mathit{p}}_{\mathrm{\ensuremath{\pi}},\mathrm{c}.\mathrm{m}.}$/${\mathit{m}}_{\mathrm{\ensuremath{\pi}}}$c between 0.099 and 0.96. The experiment was performed using an electron-cooled proton beam and an internal deuterium gas jet target. The resulting ${\mathrm{\ensuremath{\sigma}}}_{\mathrm{tot}}$ changes by almost four orders of magnitude over the covered energy range. The results are compared to a model which assumes quasi-free production via the pn\ensuremath{\rightarrow}d${\mathrm{\ensuremath{\pi}}}^{0}$ elementary process.