Table 1.

Definition of the measured observables

Observable	Definition
$p_{\mathrm{T}}^{\mathrm{Z}}$	Transverse momentum of the $Z$-boson
$N_{\text{ch}}/\mathit{\delta }\mathit{\eta }\mathit{\delta }\mathit{\varphi }$	Number of stable charged particles per unit $\mathit{\eta }$–$\mathit{\varphi }$
$\sum p_{\mathrm{T}}/\mathit{\delta }\mathit{\eta }\mathit{\delta }\mathit{\varphi }$	Scalar $p_{\mathrm{T}}$ sum of stable charged particles per unit $\mathit{\eta }$–$\mathit{\varphi }$
Mean $p_{\mathrm{T}}$	Average $p_{\mathrm{T}}$ of stable charged particles

These are defined for each azimuthal region under consideration except for $p_{\mathrm{T}}^{\mathrm{Z}}$