Search for excited electrons in pp̄ collisions at s=1.96TeV

We present the results of a search for the production of an excited state of the electron, e ∗ , in proton-antiproton collisions at √s=1.96 TeV. The data were collected with the D0 experiment at the Fermilab Tevatron Collider and correspond to an integrated luminosity of approximately 1 fb -1 . We search for e ∗ in the process pp→e ∗ e, with the e ∗ subsequently decaying to an electron plus photon. No excess above the standard model background is observed. Interpreting our data in the context of a model that describes e ∗ production by four-fermion contact interactions and e ∗ decay via electroweak processes, we set 95% C.L. upper limits on the production cross section ranging from 8.9 to 27 fb, depending on the mass of the excited electron. Choosing the scale for contact interactions to be Λ=1 TeV, excited electron masses below 756 GeV are excluded at the 95% C.L.