Cross Section Measurements of High-pTp_T Dilepton Final-State Processes Using a Global Fitting Method

We present a new method for studying high-$p_T$ dilepton events ($e^{\pm}e^{\mp}$, $\mu^{\pm}\mu^{\mp}$, $e^{\pm}\mu^{\mp}$) and simultaneously extracting the production cross sections of $p\bar{p} \to t\bar{t}$, $p\bar{p} \to W^+W^-$, and p\bar{p} \to \ztt at a center-of-mass energy of $\sqrt{s} = 1.96$ TeV. We perform a likelihood fit to the dilepton data in a parameter space defined by the missing transverse energy and the number of jets in the event. Our results, which use $360 {\rm pb^{-1}}$ of data recorded with the CDF II detector at the Fermilab Tevatron Collider, are $\sigma(t\bar{t}) = 8.5_{-2.2}^{+2.7}$ pb, $\sigma(W^+W^-) = 16.3^{+5.2}_{-4.4}$ pb, and \sigma(\ztt) =291^{+50}_{-46} pb.Comment: 20 pages, 2 figures, to be submitted to PRD-R

PRELIMINARY-RESULTS ON THE ANTICYCLOTRON AT LEAR

The KfK 'Cylotron trap' has been modified to act as a declaration and trapping device for a large number of antiprotons. An active injection device (kicker) and a pair of pulsed extraction electrodes have been placed in the cyclotron cliamber. A cylindrical e.m. trap has been added in the axial bore of the cyclotron magnet and a separation membrane has been inserted to decouple the cyclotron chamber from the high-vacuum region of the trap. We report here preliminary results of a test of this apparatus, performed at the LEAR 72 MeV/c antiproton beam

DECELERATION OF MEV ANTIPROTONS AND MUONS TO KEV ENERGIES - THE ANTICYCLOTRON - A PROGRESS REPORT

A progress report is presented on the development of the anticyclotron - deceleration of antiprotons and negative muons via collisions in a low-pressure gas or thin foils during revolutions in a cyclotron field. Beam tests performed at CERN and PSI are reported and future plans for applications outlined