Constraining $Z^{\prime }$ widths from $p_T$ measurements in Drell-Yan processes

Abstract

We define a Focus Point (FP) Asymmetry, $A_{\mathrm{FP}}$, obtained by integrating the normalised transverse momentum distribution of either lepton produced in the Drell-Yan (DY) process below and above a point where a variety of popular $Z^{\prime }$ models all have the same magnitude. For a given $Z^{\prime }$ mass the position of this FP is predictable, depending only on the collider energy and on the low transverse momentum cut chosen in the normalisation procedure. The resulting $A_{\mathrm{FP}}$ is very sensitive to the $Z^{\prime }$ width, and can be used to constrain this parameter in experimental fits.

13 pages, 15 figures