We present new measurements of differential cross sections for Z/gamma*(->mumu)+jet+X production in a 1 fb-1 data sample collected with the D0 detector in proton anti-proton collisions at sqrt{s}=1.96 TeV. Results include the first measurements differential in the Z/gamma* transverse momentum and rapidity, as well as new measurements differential in the leading jet transverse momentum and rapidity. Next-to-leading order perturbative QCD predictions are compared to the measurements, and reasonable agreement is observed, except in the region of low Z/gamma* transverse momentum. Predictions from two event generators based on matrix elements and parton showers, and one pure parton shower event generator are also compared to the measurements. These show significant overall normalization differences to the data and have varied success in describing the shape of the distributions.
We present a study of eegamma and mumugamma events using over 1 fb-1 of data collected with the D0 detector at the Fermilab Tevatron ppbar Collider at sqrt(s) = 1.96 TeV. Having observed 453 (515) candidates in the eegamma (mumugamma) final state, we measure the Zgamma production cross section for a photon with transverse energy ET > 7 GeV, separation between the photon and leptons Delta R(lgamma} > 0.7, and invariant mass of the di-lepton pair M(ll) > 30 GeV, to be 4.96 +/- 0.30(stat. + syst.) +/- 0.30(lumi.) pb, in agreement with the standard model prediction of 4.74 +/- 0.22 pb. This is the most precise Zgamma cross section measurement at a hadron collider. We set limits on anomalous trilinear Zgammagamma and ZZgamma gauge boson couplings of -0.085 < h(30)^(gamma) < 0.084, -0.0053 < h(40)^(gamma) < 0.0054 and -0.083 < h(30)^(Z) < 0.082, -0.0053 < h(40)^(Z) < 0.0054 at the 95% C.L. for the form-factor scale Lambda = 1.2 TeV.
Drell-Yan lepton pairs are produced in the process $p\bar{p} \rightarrow \mu^+\mu^- + X$ through an intermediate $\gamma^*/Z$ boson. The forward-backward asymmetry in the polar-angle distribution of the $\mu^-$ as a function of the invariant mass of the $\mu^+\mu^-$ pair is used to obtain the effective leptonic determination $\sin^2 \theta^{lept}_{eff}$ of the electroweak-mixing parameter $\sin^2 \theta_W$, from which the value of $\sin^2 \theta_W$ is derived assuming the standard model. The measurement sample, recorded by the Collider Detector at Fermilab (CDF), corresponds to 9.2 fb-1 of integrated luminosity from $p\bar{p}$ collisions at a center-of-momentum energy of 1.96 TeV, and is the full CDF Run II data set. The value of $\sin^2 \theta^{lept}_{eff}$ is found to be 0.2315 +- 0.0010, where statistical and systematic uncertainties are combined in quadrature. When interpreted within the context of the standard model using the on-shell renormalization scheme, where $\sin^2 \theta_W = 1 - M_W^2/M_Z^2$, the measurement yields $\sin^2 \theta_W$ = 0.2233 +- 0.0009, or equivalently a W-boson mass of 80.365 +- 0.047 GeV/c^2. The value of the W-boson mass is in agreement with previous determinations in electron-positron collisions and at the Tevatron collider.
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