This proposal requests support for a research program in experimental elementary particle physics at the highest laboratory energies. The two hadron collider experiments are CDF at the Fermilab Tevatron and CMS at the Large Hadron Collider (LHC) currently being built at the CERN laboratory in Geneva Switzerland. The CDF collaboration is now finishing a major upgrade of the detector for high-luminosity data taking (Run II) with the Main Injector, currently scheduled to begin on 1 March 2001. The Tevatron energy will increase from 1.8 GeV to 2.0 GeV, and the luminosity is expected to increase by an order of magnitude. Johns Hopkins University physicists are analyzing the present data set (from which the discovery of the top quark was made) while also playing crucial roles in upgrading the silicon vertex detector (SVX II) section of the CDF particle tracking system. This vertex detector is important for all charged particle tracking but is essential to find and measure secondary vertices close to the primary vertex that are characteristic of b-quark decays. Physics research in CDF by this group is concentrated on heavy quark physics and searches for new particles, especially mixing and CP-violation in b-quark decays and Higgs and supersymmetry searches. The CMS experiment will be one of two comprehensive experiments at the LHC. It will open a new energy frontier in the search for physics beyond the Standard Model, in particular the Higgs boson and supersymmetric partners of the known particles. Many of the new processes involve states with b-quarks. This group is working to develop the b-quark vertex detector capabilities of CMS. The vertex detector will use small silicon pixels to provide exceptional position resolution near the pp interaction region. This group has over a decade of experience on silicon detectors from many experiments (Mark II, SDC, CDF, and L3). The group intends its physics analysis efforts to be concentrated on using b-quark decays to study bottom and top physics and to search for phenomena on electroweak symmetry breaking, Higgs bosons, and supersymmetry. The L3 experiment is now taking LEP II data above the W+W- threshold, allowing precise measurement of W boson properties, most notably in mass and couplings, and allowing searches for new particles, especially the Higgs boson in both the Standard Model and supersymmetry. The group intends to continue to participate in L3 data taking through the end of LEP running (expected to be fall 2000) and intends to complete L3 analysis work in mid to late 2001. This group will concentrate on the search for the Higgs boson, exploring both Standard Model and supersymmetric signatures.
