Search for quark-lepton compositeness in the dimuon final state at DO

We used the upgraded DO detector at the Tevatron at s = 1.96 TeV to collect data in a search for a compositeness signature of quarks and leptons. This analysis uses an integrated luminosity of 400 pb-1. The high-mass dimuon mass spectrum is compared with that predicted by Drell-Yan (DY) scattering, modified by a contact interaction. This interaction is parameterized by a compositeness energy scale factor Λ. Preliminary limits on Λ are set at the 95% confidence level for constructive and destructive interference between the DY amplitude and the contact interaction for various quark and lepton chiralities.