CROSS-SECTION FOR DOUBLE CHARMONIUM PRODUCTION IN ELECTRON–POSITRON ANNIHILATION AT ENERGY $\sqrt{s} = 10.6 {\rm GeV}$

Abstract

In this work we study the process e++e-→J/Ψ+ηc at energy [Formula: see text] observed recently at B-factories whose measurements were made by Babar and Belle groups. We calculate the cross-section for this process in the Bethe–Salpeter formalism under Covariant Instantaneous Anstaz. To simplify our calculation, the heavy quark approximation is employed in the quark and gluon propagators. In the exclusive process of e+e- annihilation into two heavy quarkonia, the cross-section calculated in this scenario is compatible with the experimental data of Babar and Belle.