Study of Z Pair Production and Anomalous Couplings in e+e- Collisions at sqrt(s) between 190 GeV and 209 GeV

TL;DR

This paper investigates Z-boson pair production in electron-positron collisions at energies between 190 and 209 GeV, analyzing various final states to measure cross sections and set limits on anomalous couplings and theories of extra dimensions.

Contribution

It provides new measurements of Z-pair production cross sections and establishes constraints on anomalous ZZgamma and ZZZ couplings, as well as on low scale gravity models with large extra dimensions.

Findings

Measured cross sections for Z-pair production at specified energies.

Set limits on anomalous ZZgamma and ZZZ couplings.

Derived constraints on models of low scale gravity with large extra dimensions.

Abstract

A study of Z-boson pair production in e+e- annihilation at center-of-mass energies between 190 GeV and 209 GeV is reported. Final states containing only leptons, (l+l-l+l- and l+l-nn), quark and lepton pairs, (qql+l-, qqnn) and only hadrons (qqqq) are considered. In all states with at least one Z boson decaying hadronically, lifetime, lepton and event-shape tags are used to separate bb pairs from qq final state. Limits on anomalous ZZgamma and ZZZ couplings are derived from the measured cross sections and from event kinematics using an optimal observable method. Limits on low scale gravity with large dimensions are derived from the cross sections and their dependence on polar angle.