Measurement of the High Mass Dimuon Continuum Produced in Antiproton-Nucleus Collisions At 125 Gev/C.

Abstract

The preliminary results of measurements of the absolute differential cross sections in dimuon mass, Feynman x, and transverse momentum at 125 GeV/c for antiproton-nucleon interactions are presented. The data are for events on tungsten with M(,(mu)(mu)) > 4.0 GeV/c('2) and x(,F) > 0. The cross sections are tabulated and fit to empirical functions. Comparisons of the experimental cross sections are made to the predictions of the naive Drell-Yan model for this process. The K factor, defined as the ratio of the empirical cross section to the calculated Drell-Yan cross section, is measured and the value reported is 2.25 (+OR-) .45 for p-N interactions. The K factor is compared to the results of other experiments and to QCD calculations of K to order (alpha)(,s). The results reported are from experiment E-537 performed in the High Intensity Laboratory in the proton area at Fermilab. This experiment was the first to make use of the unique antiproton enriched beam available in this area. The apparatus, consisting of a large aperture, forward spectrometer for detecting final state muons and a beam particle identification and momentum tagging system, is described in detail. The data analysis techniques used to extract the cross sections are discussed, with particular emphasis given to the track reconstruction procedure from drift chamber observations.