LEP $e^{+}\,e^{-}\,\rightarrow\,\mu^{+}\, \mu^{-}\,\gamma\,\gamma$ events and their consequences at future $e^+e^-$ colliders

Abstract

The $e^{+}\,e^{-}\,\rightarrow\,l^{+}\, \l^{-}\,\gamma\,\gamma$ anomalous events, detected by $L3$ de\-tec\-tor at $e^+ e^-$ $CERN-LEP$ collider have been analysed. It has been shown that the interpretation of such events as a manifestation of scalar (pseudoscalar) resonance with the mass of 60 GeV contradicts other experimental data. In case of a possible existence that kind of resonance, the perspectives to discover one in some processes at future $e^+e^-$ colliders have been discussed.