Upper limit for the cross section of the overlapping scalar resonances f₀(980) and a₀(980) produced in proton-proton collisions in the range of the reaction threshold

Abstract

Utilizing a missing mass technique we investigate the pp->ppX reaction scanning beam energies in the range permitting to create a mass close to that of the f₀(980) and a₀(980) scalar resonances, but still below the K⁺K^- threshold where they decay dominantly into pi pi and pi eta mesons, respectively. Prior to the data analysis we introduce a notion of the close to threshold total cross section for broad resonances. We estimated for the overlapping mesons a₀ and f₀ the total cross section to be smaller than 430 nb at excess energy of Q = 5 MeV. The experiment have been performed at the Cooler Synchrotron COSY using the COSY-11 facility.

E-print: http://xxx.lanl.gov/abs/nucl-ex/0307016
J.Phys. G 29 (2003) 2235-2245