Measurements of the inclusive diffractive Z → ?+?- cross section with gap requirement for M?? > 40 GeV at √s = 1.96 TeV and fraction of Z bosons produced diffractively with gap requirement from Z inclusive production are presented. The measurements are performed using a data sample corresponding to an integrated luminosity of 820 pb-1, collected with the D0 detector at the Tevatron, between 2002 to 2005. A total of 39945 di-muons events are selected and final results of: ?$gaptop{Diff}$ x Br(Z/?* → ?+?-) = 4.09 ± 0.64(stat.) ± 0.88(syst.) ± 0.27(lumi.) pb and, R$gaptop{Diff}$ = 1.92 ± 0.30(stat.) ± 0.41(syst.) ± 0.12(lumi) % are obtained. In addition, d?/d? and d?/dy distributions are presented and they are compared with diffractive montecarlo (POMWIG). A reasonable agreement is obtained in this comparation. Finally, comparison of fraction of Z bosons produced diffractively with gap requirement (gap fraction) as measured with D0 during Run I of the Tevatron is compared. A good agreement is found for gap fraction results.

We present a search for exclusive Z boson production in proton-antiproton collisions at √s = 1.96 TeV, using the CDF II detector at Fermilab. We observe no exclusive Z → l+l− candidates and place the first upper limit on the exclusive Z cross section in hadron collisions, [sigma]{sub excl}(Z) 0.96 pb at 95% confidence level. In addition, we observe eight candidate exclusive dilepton events from the quantum electrodynamic process p{bar p} → p[gamma][gamma]{bar p} → pl+l− {bar p}, and measure the cross section for M{sub l{ell}} 40 GeV=c2 and.

We present a search for exclusive Z boson production in proton-antiproton collisions at √s = 1.96 TeV, using the CDF II detector at Fermilab. We observe no exclusive Z → ll− candidates and place the first upper limit on the exclusive Z cross section in hadron collisions,?{sub excl}(Z) 0.96 pb at 95% confidence level. In addition, we observe eight candidate exclusive dilepton events from the quantum electrodynamic process p{bar p} → p??{bar p} → pl+l− {bar p}, and measure the cross section for M{sub l{ell}} 40 GeV=c2 and.

High-precision measurements are made of Z boson production in proton-antiproton collisions at √s = 1.96 TeV recorded by the Collider Detector at Fermilab, using the electron decay channel. The cross-section times branching ratio is measured to be ?Z · Br(Z → e+e-) = (255.7 ± 2.4stat ± 5.2sys ± 15.2lum)pb in a dataset of 194 pb-1 collected between March 2002 and June 2003. This agrees well with theoretical predictions. The cross-section for W boson production in the electron channel has also been measured in the subset of this dataset of 72 pb-1 collected up until January 2003. Using this smaller dataset the ratio of cross-sections is determined to be R ≡ ?W · Br(W → e?)/?Z · Br(Z → ee) = 10.82 ± 0.18stat ± 0.16sys. Combining these results with measurements made in the muon channel gives R = 10.92 ± 0.15stat ± 0.14sys (e + ? channels), from which the branching ratio of the W to electrons and muons, and the total width of the W, have been extracted: Br(W → l?) = 0.1089 ± 0.0022 (l = e,?); ?(W) = 2078.8 ± 41.4 MeV, which are in good agreement with the Standard Model values and with other measurements. The CKM quark mixing matrix element.

The theory that describes the fundamental particle interactions is called the Standard Model, which is a gauge field theory that comprises the Glashow-Weinberg-Salam model [1, 2, 3] of the weak and electromagnetic interactions and quantum chromodynamics (QCD) [4, 5, 6], the theory of the strong interactions. The discovery of the W [7, 8] and Z [9, 10] bosons in 1983 by the UA1 and UA2 collaborations at the CERN p$\bar{p}$ collider provided a direct confirmation of the unification of the weak and electromagnetic interactions. Since then, many experiments have refined our understanding of the characteristics of the W and Z bosons.

This dissertation describes a measurement of the shape of the boson transverse momentum distribution in p{bar p} 2!Z/[gamma]* 2!ee− + X events at a center-of-mass energy of 1.96 TeV. The measurement is made for events with electron-positron mass between 70