A search for excited fermions at HERA

A search for excited fermions f* of the first generation in e+p scattering at the collider HERA is presented using H1 data with an integrated luminosity of 37pb-1. All electroweak decays of excited fermions, f*→fγfW,fZ are considered and all possible final states resulting from the Z or W hadronic decays or decays into leptons of the first two generations are taken into account. No evidence for f* production is found. Mass dependent exclusion limits on cross-sections and on the ratio of coupling constants to the compositeness scale are derived. (orig.)