Two-proton correlation function for the pp pp + and pp pp + pions reactions

International audience; For the very first time, the correlation femtoscopy method is applied to a kinematically complete measurement of meson production in the collisions of hadrons. A two-proton correlation function was derived from the data for the pp → ppX reaction, measured near the threshold of η meson production. A technique developed for the purpose of this analysis permitted to establish the correlation function separately for the production of the pp + η and of the pp + pions systems. The shape of the two-proton correlation function for the ppη differs from that for the pp(pions) and both do not show a peak structure opposite to results determined for inclusive measurements of heavy ion collisions.