  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.
