Eur. Phys. J. A (2004) 21: 507-520
https://doi.org/10.1140/epja/i2004-10004-2

Near-threshold production of a₀(980)-mesons in the reaction

¹ Institute for Nuclear Research, 60th October Anniversary Prospect 7A, 117312, Moscow, Russia
² Institute of Theoretical and Experimental Physics, B. Cheremushkinskaya 25, 117259, Moscow, Russia
³ Institut für Kernphysik, Forschungszentrum Jülich, D-52425, Jülich, Germany
⁴ Institut für Theoretische Physik, Universität Giessen, Heinrich-Buff-Ring 16, D-35392, Giessen, Germany

^* e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

Using an effective Lagrangian approach as well as the Quark-Gluon Strings Model, we analyze near-threshold production of a ₀(980)-mesons in the reaction as well as the background of non-resonant -pair production. We argue that the reaction at an energy release MeV is dominated by the intermediate production of the a ₀(980)-resonance. At larger energies the non-resonant -pair production --where the kaons are produced in a relative P-wave-- becomes important. The effects of final-state interactions are evaluated in a unitarized scattering length approach and found to be in the order of a 20% suppression close to threshold. Thus, in present experiments at the Cooler Synchrotron COSY-Jülich for MeV the a ₀ ⁺ signal can reliably be separated from the non-resonant background.