TESLA: potentials of γγ and e +e − options in stoponium searches

Abstract

In some supersymmetric extensions of the Standard Model fairly light superpartner of t-quark is predicted, which may form bound states ( stoponiums) under certain conditions. We estimate potentials of TESLA linear collider in search for stoponium, considering the basic electron–positron option and the γγ option (Photon Linear Collider—PLC). It is found that PLC could be the best machine for discovery and study of these new narrow strong resonances. It can produce thousands stoponiums per 100 fb −1 integrated γγ luminosity in the high energy peak. In the case of scenarios, when stoponium decays mainly into two gluons the signal/ background ratio is about 1 4 . In addition, the decay channel S→hh into two lightest Higgs bosons could be seen with high significance. Thus, several weeks run is sufficient for the discovery of stoponium, if its mass is approximately known (for example, from observation of direct stops production at LHC). Then, in MSSM scenarios with dominant S→hh decay PLC shows excellent possibilities to discover bound state of stops, practically immediately after beginning of operating. Thus, PLC has good possibilities to study strong interaction of top quark superpartners in nonperturbative regime. The e +e − option also has some prospects to observe stoponium but only in the case of scenarios with dominant decay into two lightest Higgs bosons, with tens of events per 100 fb −1 . Interesting possibility appears in the case when the resonance is seated on 0.1% width luminosity peak—one could resolve the stoponium exited states.