The production cross section and the QCD higher order cotribution, K factor of Drell-Yan process have been measured in dielection mode in proton-antiproton collisions at the center of mass energies of 1800 GeV. The experiment has been performed at Fermi National Accelerator Laboratory in the United States using Tevatron accelerator during the period of 1988 though 1989. A number of physics quantities are measured using the CDF(Collider Detector at Fermilab) detector in the pseudorapidity range -2.4 < η < 2.4. Total integrated luminosity used for this analysis is .4 pb-1. The cross section has been measured down to [?]r = 0.0066 which is much lower than measured before. Both the cross section and the K factor are compared with theoretical predictions calculated with a number of different parton distribution functions. Since the production cross section depends both on the K factor and parton distribution functions, the discussion will be done from two points of view. The discussion starts from K factor measurement. The K factor has been measured in Z0 mass region at first, then assuming that the K factor is constant over the invariant mass region 10 <M <105, the behavior of parton distribution function in a low mass region (12 <M <30) is discussed. According to the theoretical prediction of K factor, this assumption is good approximation in the measured mass region independently of parton distribution functions. The Z0 production cross section times branching ratio of (z0 [?] e+e-) was 205.5 [?] 13.82(sta) [?] 16.0(sys) [?] 15.4(lum) (pb). The K factor, assuming HMRSB parton ditribution function, is measured to be 1.53 [?] 0.4. The parton distributions function EHLQ1, HMRSE and HMRSB reproduces the date well. The production properties of the Drell-Yan process are also studied. The rapidity distribution and Pt spectrum of the parent virtual photon or Z0 are presented, as well as the decay electron angular distribution, the Pt spectrum in the center-of-mass system. All these quantities are consistent with Monte Carlo simulation data using EHLQ1 parton distribution function within the error. Finally a comparison is made between dielectrons from the Drell-Yan process and heavy flavor productions.Thesis--University of Tsukuba, D. Sc.(B), no. 651, 1991. 2. 2
