Has the Substructure of Quarks and Leptons Been Found also by the H1 and ZEUS Detectors at HERA?

Abstract

The significant excess of events recently found by the H1 and ZEUS Collaborations at HERA in the deep-inelastic e^+ p scattering for high momentum-transfers squared Q^2>15000 GeV^2 over the expectation of the standard model can be explained by either one of the following possible consequences of the substructure of quarks and leptons: 1) production of leptoquarks (Phi), 2) exchange of an excited Z boson (Z'), 3) intrinsic form factors of quarks (or leptons), 4) intrinsic anomalous magnetic moments of quarks, 5) production of excited quarks (q^*), and 6) that of excited positrons (e^*+). The masses of these new particles are estimated to be m(Phi) = 280-440 GeV, m(Z') = 210-250 GeV, m(q^*) = 120-140 GeV, and m(e^*+) = 300-370 GeV, although the possibilities 2) and 5) are excluded by the currently available experimental constraints.

7 pages, revtex, 2 Postscript figures

References in corpus (5)

• Comparison of ZEUS Data with Standard Model Predictions for e^+ p -> e^+ X Scattering at High x and Q^2
• Observation of Events at Very High Q^2 in ep Collisions at HERA
• R-Parity Violation at HERA ?
• QCD aspects of leptoquark production at HERA
• Contact Interactions and high-Q2 events in e^+ p collisions at HERA

Cited by in corpus (2)

• Global Study of Electron-Quark Contact Interactions
• Impact on SUSY-Breaking Models of the $R$-Parity Violating Squark Interpretation of the HERA Anomaly