Abstract
Measurements of differential cross sections d\(\sigma\)/d\(\phi^*\) and double-differential cross sections d\(^2\sigma\)/d\(\phi^*\,\)d\(|y|\) for inclusive Z boson production are presented using the dielectron and dimuon final states. The kinematic observable \(\phi^*\) correlates with the dilepton transverse momentum but has better resolution, and \(y\) is the dilepton rapidity. The analysis is based on data collected with the CMS experiment at a centre-of-mass energy of 8 TeV corresponding to an integrated luminosity of 19.7 fb\(^{-1}\). The normalised cross section (1/\(\sigma\))\(\,\)d\(\sigma\)/d\(\phi^*\), within the fiducial kinematic region, is measured with a precision of better than 0.5% for \(\phi^*\) < 1. The measurements are compared to theoretical predictions and they agree, typically, within few percent.