A Measurement of the Z Boson Transverse Momentum Distribution, and of the ZZ and WZ Production Cross SectionsUsing 7.3-8.6 fb$^{-1}$ of $p\bar{p}$ Collisions at $sqrt{s}$ = 1.96 TeV

Abstract

Two analyses are performed with the large samples of dielectron and dimuon eventscollected by the D0 experiment at the Fermilab Tevatron $p\bar{p}$ collider.The dilepton transverse momentum ($p_T$) distribution in \zll\ production is a powerful probe of Quantum chromodynamics.Until now, this distribution has been measured with limited precision.An alternative variable, \phistar, is proposed due to its relatively low susceptibility to detector effects.The \phistar\ distribution of events with \zll\ invariant masses between 70 and 110~GeV,is measured in three bins of dilepton rapidity.This measurement, with 7.3 fb$^{-1}$ of data, is significantly more precise than previous measurementsof the $p_T$ distribution.A state-of-the-art QCD Monte Carlo program is in modest agreement with the data.Using 8.6 fb$^{-1}$ of data, the\zzllnunu\ and \wzlllnu\ processes are studied, yieldingproduction cross sections of,$\sigma(p\bar{p} \rightarrow ZZ/\gamma^*)$ = 1.64 $\pm$ 0.46 pb and$\sigma(p\bar{p} \rightarrow WZ/\gamma^*)$ = 4.46 $\pm$ 0.64 pb,for \zll\ invariant masses between 60 and 130~GeV.These are in agreement with Standard Model predictions.

Date of Award	1 Aug 2012
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Terence Wyatt (Supervisor)