The FOCUS experiment is being carried out by an international collaboration of physicists from universities and national laboratories. These researchers are performing high-statistics experimental studies of the production and decay of the charm quark, the third heaviest quark found in nature.

The collaboration has accumulated one of the largest samples of charm quark decays in the world, using a high-energy photon beam and the FOCUS spectrometer, which is located in the Wide-Band Laboratory of the Fermi National Accelerator Laboratory (Fermilab) near Chicago, Illinois. The FOCUS experiment is an upgraded version of its predecessor, E687.

FOCUS has published prolifically.

Vanderbilt physicists have made several contributions to the installation, commissioning, and operation of the experiment. One significant contribution was the construction (pictures) of a new Outer Muon Detector Array for the experiment. The active part of the detector uses resistive plate chambers (RPCs) with a strip readout geometry. Muon identification impacts many of the physics goals of FOCUS: semileptonic decay studies, searches for fully leptonic and rare and forbidden charm decays, and J/psi and Upsilon production studies.

This research is supported by the National Science Foundation under Grants SCI-0121658 and PHY-0600694.