[en] The authors propose to add high precision track detectors 55 m downstream on both (E and W) sides of CDF, to measure high Feynman-x protons and antiprotons in association with central states. A primary motivation is to search for the Higgs boson, and if it is seen to measure its mass precisely. The track detectors will be silicon strip telescopes backed up by high resolution time-of-flight counters. They will have four spectrometer arms, for both sides of the p and (bar p) beams. The addition of these small detectors effectively converts the Tevatron into a gluon-gluon collider with √s from 0 to ∼ 200 GeV. This experiment also measures millions/year clean high- |t| elastic p(bar p) scattering events and produce millions of pure gluon jets. Besides a wealth of other unique QCD studies they will search for signs of exotic physics such as SUSY and Large Extra Dimensions. They ask the Director to ask the PAC to take note of this Letter of Intent at its April meeting, to consider a proposal at the June meeting and to make a decision at the November 2001 meeting. They request that the Directorage ask the Beams Division to evaluate the consequences and cost of the proposed Tevatron modifications, and CDF to evaluate any effect on its baseline program and to review the technical aspects of the detectors, DAQ and trigger integration.