Pursuing the Strange Stop Interpretation of the HERA Large Q^2 data

Abstract

We explore the possible interpretation of the large-$Q^2$ anomaly reported by the H1 and ZEUS collaborations in terms of stop squark production off a strange quark in the proton via an R-violating interaction. This "strange stop" interpretation is constrained by LEP measurements of the $Z \to e^+ e^-$ decay rate in addition to constraints from the electroweak $ρ$ parameter and CDF and D0 searches for first-generation leptoquarks. We investigate the interplay between these constraints, taking full account of stop mixing effects. We find that if $m_{\tilde t} \le 200$ GeV only relatively small domains of the chargino and neutralino parameters are consistent with these constraints, and explore the extent to which this scenario may be probed further by searches for contact interactions at LEP~2 and experiments with $e^-$ and polarized beams at HERA.