HERA high $Q^2$ events as indications of excited leptons with weak isotopic spin 3/2

Abstract

The H1 and ZEUS anomalous events are interpreted as being due to the production and the decay of excited leptons $E$, which correspond to spin 1/2 resonances of the first generation lepton doublet ($\nu_e, e$) with W triplet. This assumption is supported by considering of Bethe-Salpeter equation in the ladder approximation with anomalous triple gauge boson vertex. The solution with weak isospin $I = 3/2$ is shown to exist for zero mass state, that means M_E$ is small in comparison with TeV mass scale. The coupling of $E$ with leptons and $W$ is defined by the normalization condition. Calculation of the $E$ width and the production cross-sections agrees with HERA data for value of the triple $W$ coupling constant $\lambda \simeq 0.5$. Isotopic relations for different channels are presented as a tool for checking the interpretation.