Two analyses are performed with the large samples of dielectron and dimuon events collected by the D0 experiment at the Fermilab Tevatron $p\bar{p}$ collider. The dilepton transverse momentum ($p_T$) distribution in $Z/\gamma^* → \ell^+\ell^-$ production is a powerful probe of Quantum chromodynamics. Until now, this distribution has been measured with limited precision. An alternative variable, $\phi^*_\eta$, is proposed due to its relatively low susceptibility to detector effects. The $\phi^*_\eta$, distribution of events with $Z/\gamma^* → \ell^+\ell^-$ invariant masses between 70 and 110 GeV, is measured in three bins of dilepton rapidity. This measurement, with 7.3 fb$^{-1}$ of data, is significantly more precise than previous measurements of the $p_T$ distribution. A state-of-the-art QCD Monte Carlo program is in modest agreement with the data. Using 8.6 fb$^{-1}$ of data, the $ZZ/\gamma^* → \nu\bar{\nu}\ell^+\ell^-$ and $WZ/\gamma^* → \ell\nu\ell^+\ell^-$ processes are studied, yielding production cross sections of, $\sigma(p\bar{p} \rightarrow ZZ/\gamma^*)$ = 1.64 $\pm$ 0.46 p b and $\sigma(p\bar{p} \rightarrow WZ/\gamma^*)$ = 4.46 $\pm$ 0.64 pb, for $Z/\gamma^* → \ell^+\ell^-$ invariant masses between 60 and 130 GeV. These are in agreement with Standard Model predictions.

We present a measurement of the Z boson differential cross section in rapidity and transverse momentum using a data sample of pp collision events at a centre-of-mass energy √s=8 TeV, corresponding to an integrated luminosity of 19.7 fb-1. The Z boson is identified via its decay to a pair of muons. The measurement provides a precision test of quantum chromodynamics over a large region of phase space. In addition, due to the small experimental uncertainties in the measurement the data has the potential to constrain the gluon parton distribution function in the kinematic regime important for Higgs boson production via gluon fusion. The results agree with the next-to-next-to-leading-order predictions computed with the fewz program. The results are also compared to the commonly used leading-order MadGraph and next-to-leading-order powheg generators.

The ZZ production cross section in proton-proton collisions at 13 TeV center-of-mass energy is measured using 3.2 fb–1 of data recorded with the ATLAS detector at the Large Hadron Collider. The considered Z boson candidates decay to an electron or muon pair of mass 66–116 GeV. The cross section is measured in a fiducial phase space reflecting the detector acceptance. It is also extrapolated to a total phase space for Z bosons in the same mass range and of all decay modes, giving 16.7+2.2–2.0(stat)+0.9–0.7(syst)+1.0–0.7(lumi) pb. Lastly, the results agree with standard model predictions.