Low-energy pion-pion scattering in the pp→ppπ~+π~-andpp — ppπ~+π~+reactions

摘要

We evaluate the contribution of pion-pion rescattering to the pp -p ppπ+π- and pp -> pPπ +π- reac-tions. We compare our results with the close-to-threshold experimental data. The pion-pion rescatteringcontribution is found there to be negligible. The predictions for future experiments with PANDA detec-tor at High Energy Storage Ring (HESR) in GSI Darmstadt are presented. It is discussed how to cut offthe dominant Roper resonance and double-A excitation mechanisms leading to the ppπ+π- channel infinal state. Differential distributions in momentum transfers, transverse momentum, effective two-pionsmass, relative azimuthal angle between pions, and pion rapidiVes are presented.