$P$-wave dibaryon resonances in $pp$ elastic scattering and near-threshold pion production

Abstract

It is demonstrated within the dibaryon-induced model for $NN$ interaction that $pp$ scattering in $P$ waves is governed mainly by the production of the intermediate dibaryon resonances. Two dibaryon resonances with a mass of about 2200 MeV discovered recently by the ANKE-COSY Collaboration are shown to determine both elastic $pp$ phase shifts and inelasticities in the ${}^3{P}_0$ and ${}^3{P}_2$-${}^3{F}_2$ channels from zero energy up to $T_p=0.7$-$0.9$ GeV. It is also demonstrated clearly that the ${}^3{P}_0$ dibaryon plays a decisive role in near-threshold neutral pion production in $pp$ collisions which is poorly understood to date. The missing dibaryon contribution is found to be the very possible reason for the failure of traditional approaches to explain near-threshold ${\pi }^0$ production.

Comments: 12 pages, 11 figures; version accepted for publication in PRD