Search for excited electrons in ep collisions at HERA

A search for excited electrons is performed using the full e ± p data sample collected by the H1 experiment at HERA, corresponding to a total luminosity of 475 pb −1 . The electroweak decays of excited electrons e ∗ → e γ , e ∗ → e Z and e ∗ → ν W with subsequent hadronic or leptonic decays of the W and Z bosons are considered. No evidence for excited electron production is found. Mass dependent exclusion limits on e ∗ production cross sections and on the ratio f / Λ of the coupling to the compositeness scale are derived within gauge mediated models. These limits extend the excluded region compared to previous excited electron searches. The e ∗ production via contact interactions is also addressed for the first time in ep collisions.