Using leptons $p_T$ measurements to constrain $Z^\prime$-bosons widths in Drell-Yan processes at the LHC

We recognise the appearance of a Focus Point (FP) in the transverse momentum distribution of either leptons originating from a BSM $Z^\prime$-boson decay, after a simple normalisation procedure. Exploring the properties of the FP we will be able to define in a general way a new observable, the Focus Point Asymmetry ($A_{\rm FP}$), which can be used to set constrains on the $Z^\prime$ width. We discuss the potential and the sensitivity of the $A_{\rm FP}$ in as diagnostic tool for $Z^\prime$ physics, considering various $Z^\prime$ phenomenological realisations.