Search for excited quarks in ep collisions at HERA

A search for excited quarks is performed using the full e±p data sample collected by the H1 experiment at HERA, corresponding to a total integrated luminosity of 475pb−1. The electroweak decays of excited quarks q∗→qγ, q∗→qZ and q∗→qW with subsequent hadronic or leptonic decays of the W and Z bosons are considered. No evidence for first generation excited quark production is found. Mass dependent exclusion limits on q∗ 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 quark searches.