The largest Feynman diagram in the world?

As far as I know, the Feynman diagram embedded in the atrium floor of our physics building is the largest in the world. I often overhear campus tour guides describe the diagram as a kind of "molecule" :-/





It's hard to see in the photos, but the diagram is of the Drell-Yan process, where a quark and antiquark fuse into a photon or other gauge boson, which then decays to a lepton-antilepton pair.