Executive Summary

We propose to add a Time-of-Flight(TOF) system to CDF that will allow the tagging of soft kaons and protons. Such an addition will significantly improve a broad spectrum of B physics capabilities for CDF. The proposed TOF system will have a resolution near 100 ps and will be capable of identifying kaons from pions by their flight time difference with at least 2 separation up to kaon momenta of 1.6 GeV/c. This capability is well matched to the soft kaon momentum spectrum from B decay and will be useful for reconstructing many exclusive charm and bottom decay modes, such as , where and . In addition, the efficiency for reconstruction of semi-leptonic decays of B mesons such as , where should be improved. Kaon identification will also enable CDF to self-tag mesons which is useful for -mixing measurements. Background rejection for rare B decay studies such as will be improved. Finally, the prospect exists for CDF to observe CP violation in the decay during Run-II. We view the addition of the TOF system as part of an overall upgrade to improve the CDF detector for the study of B physics. The TOF detector envisioned would reside just inside the CDF coil and outside the central tracking chamber in the location presently occupied by the Central Drift Tubes. Such a system represents a moderate upgrade project that is compatible with most existing CDF equipment and consistent with our long term upgrade plans. Tests of full sized prototype TOF counters for the proposed system indicate that a practical TOF system for CDF can be built quickly and will operate with resolutions approaching 100 ps. The system could be installed for Run-II and will cost about $1 M.