Current constraints on squark production scenarios for the excess of high Q² events at HERA

We examine the stop production scenario for the excess of high Q² events observed at HERA, by taking into account the constraints coming from the leptoquark search at Tevatron and the atomic parity violation approximation; experiments. This scenario is shown to survive persistently even under the severe constraints from the other experiments. In the analysis, the branching ratios B_t̃j. of the decay modes t̃_j→ed (j = 1,2) are found to be useful parameters, representing a number of unknown parameters in the SUSY models. By expressing the stop contribution to the cross section of deep inelastic ep scattering σ(ep → eX) in terms of B_t̃1 and B_t̃1, the allowed region is successfully identified in the parameter space of Bf and B_t̃2. We can also apply our analysis to future experiments of ep scattering including ep collisions in 1998-1999 at HERA.