Abstract
Recent calculations of s-wave pion production have severely underestimated the accurately known pp\ensuremath{\rightarrow}pp${\mathrm{\ensuremath{\pi}}}^{0}$ total cross section near threshold. In these calculations, only the single-nucleon axial-charge operator is considered. We have calculated, in addition to the one-body term, the two-body contributions to this reaction that arise from the exchange of mesons. We find that the inclusion of the scalar \ensuremath{\sigma}-meson exchange current (and lesser ocntributions from other mesons) increases the cross section by about a factor of 5 and leads to excellent agreement with the data. The results are sensitive neither to changes in the distorting potential that generates the NN wave functions nor to different choices for the meson-nucleon form factors.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.