Measurement of $ZZ$ Production in Leptonic Final States at $\surd{s}$ of 1.96 TeV at CDF.

Measurement of $ZZ$ Production in Leptonic Final States at $\surd{s}$ of 1.96 TeV at CDF.
Author:
Publisher:
Total Pages:
Release: 2011
Genre:
ISBN:

In this paper we present a precise measurement of the total ZZ production cross section in p{bar p} collisions at √s = 1.96 TeV, using data collected with the CDF II detector corresponding to an integrated luminosity of approximately 6 fb−1. The result is obtained by combining separate measurements in the four-charged (lll′l′), and two-charged-lepton and two-neutral-lepton (ll??) decay modes of the Z. The combined measured cross section for p{bar p} → ZZ is 1.64{sub -0.38}{sup +0.44} pb. This is the most precise measurement of the ZZ production cross section in 1.96 TeV p{bar p} collisions to date.

Measurement of the ZZ Production Cross Section and Z {u2192} L+l{u2013}l'+l'{u2013} Branching Fraction in Pp Collisions at

Measurement of the ZZ Production Cross Section and Z {u2192} L+l{u2013}l'+l'{u2013} Branching Fraction in Pp Collisions at
Author:
Publisher:
Total Pages: 24
Release: 2016
Genre:
ISBN:

Here, four-lepton production in proton–proton collisions, pp→(Z/?*)(Z/?*)→l+l–l'+l'–,where l,l'=e or ?, is studied at a center-of-mass energy of 13 TeV with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 2.6 fb–1. The ZZ production cross section, ?(pp → ZZ)=14.6–1.8+1.9(stat)–0.3+0.5(syst)±0.2(theo)±0.4(lumi)pb, is measured for events with two opposite-sign, same-flavor lepton pairs produced in the mass region 60msublsup+/suplsup–/sup/sub,ml'sup+/supl'sup–/sup120 GeV60mlsup+/suplsup–/sup,ml'sup+/supl'sup–/sup120 GeV. The Z boson branching fraction to four leptons is measured to be B(Z→lsup+/suplsup–/supl'sup+/supl'sup–/sup)=4.9sub–0.7/subsup+0.8/sup (stat)sub–0.2/subsup+0.3/sup (syst)–0.1+0.2(theo)±0.1(lumi)×10sup–6/sup for the four-lepton invariant mass in the range 80mlsup+/suplsup–/supl'sup+/supl'sup–/sup100 GeV80mlsup+/suplsup–/supl'sup+/supl'sup–/sup

Measurement of the TtZ Production Cross Section in the Final State with Three Charged Leptons Using 36.1 Fb^-1 of Pp Collisions at 13 TeV at the ATLAS Detector

Measurement of the TtZ Production Cross Section in the Final State with Three Charged Leptons Using 36.1 Fb^-1 of Pp Collisions at 13 TeV at the ATLAS Detector
Author: Nils-Arne Rosien
Publisher:
Total Pages: 0
Release: 2017
Genre:
ISBN:

A measurement of the production cross section for a top quark pair in association with a Z boson (ttZ) is presented in this PhD thesis. Final states with exactly three charged leptons (electrons or muons) are used, taking into account the decay of the top quark pair in the lepton+jets channel and the decay of the Z boson into two charged leptons. The dataset used for this analysis corresponds to 36.1 fb^-1 of proton-proton collisions at a centre-of-mass energy of 13 TeV, recorded during 2015 and 2016 by the ATLAS detector at the Large Hadron Collider. The result of a profile likelihood fit ...

Measurement of the Pp {u2192} ZZ Production Cross Section and Constraints on Anomalous Triple Gauge Couplings in Four-lepton Final States at {u221A}s

Measurement of the Pp {u2192} ZZ Production Cross Section and Constraints on Anomalous Triple Gauge Couplings in Four-lepton Final States at {u221A}s
Author:
Publisher:
Total Pages: 23
Release: 2014
Genre:
ISBN:

A measurement of the inclusive ZZ production cross section and constraints on anomalous triple gauge couplings in proton–proton collisions at √s = 8 TeV are presented. The analysis is based on a data sample, corresponding to an integrated luminosity of 19.6 fb−1, collected with the CMS experiment at the LHC. The measurements are performed in the leptonic decay modes ZZ → lll'l', where l = e,? and l' = e,?,?. The measured total cross section ?(pp → ZZ) = 7.7 ± 0.5 (stat)-0.4+0.5 (syst) ± 0.4 (theo) ± 0.2 (lumi) pb, for both Z bosons produced in the mass range 60 msubZ/sub 120 GeV, is consistent with standard model predictions. Differential cross sections are measured and well described by the theoretical predictions. As a result, the invariant mass distribution of the four-lepton system is used to set limits on anomalous ZZZ and ZZ? couplings at the 95% confidence level: –0.004 fsub4/subsupZ/sup 0.004, –0.004 fsub5/subsupZ/sup 0.004, –0.005 fsub4

Measurements of ZZ Production Cross Section Using Four-lepton Events and Constraints on Anomalous Triple Gauge Couplings at [squareroot]s

Measurements of ZZ Production Cross Section Using Four-lepton Events and Constraints on Anomalous Triple Gauge Couplings at [squareroot]s
Author: Usama Hussain
Publisher:
Total Pages: 0
Release: 2020
Genre:
ISBN:

Studies of four-lepton production in proton-proton collisions, pp → (Z/[gamma]*)(Z/[gamma]*)→ 4l, where l = e or [mu], using data collected during 2016-2018 (Run II) are presented. The dataset corresponds to an integrated luminosity of 137 fb^(−1) at a center-of-mass energy of 13 TeV, collected by the CMS detector at the LHC. All reported measurements use the 2l2l' final states, where l,l' = e or [mu]. The total ZZ cross section for all events with two Z bosons in the mass range 60-120 GeV is measured and found to be [sigma](pp → ZZ) = 17.2 ± 0.3 (stat) ± 0.5 (syst) ± 0.4 (theo) ± 0.3 (lumi) pb. Differentialcross sections are measured as functions of a number of kinematic observables. Allthese results agree with standard model predictions. Searches for anomalous triplegauge couplings are performed, and the four-lepton invariant mass distributions areused to set the most stringent limits to date on a number of parameters affectingneutral gauge boson interactionsl

Measurement of the Pp 2!ZZ Production Cross Section and Constraints on Anomalous Triple Gauge Couplings in Four-lepton Final States at [arrow]"

Measurement of the Pp 2!ZZ Production Cross Section and Constraints on Anomalous Triple Gauge Couplings in Four-lepton Final States at [arrow]
Author:
Publisher:
Total Pages: 23
Release: 2014
Genre:
ISBN:

A measurement of the inclusive ZZ production cross section and constraints on anomalous triple gauge couplings in proton-proton collisions at [arrow]" = 8 TeV are presented. The analysis is based on a data sample, corresponding to an integrated luminosity of 19.6 fb−1, collected with the CMS experiment at the LHC. The measurements are performed in the leptonic decay modes ZZ 2!lll'l', where l = e, [mu] and l' = e, [mu], [tau]. The measured total cross section [sigma](pp 2!ZZ) = 7.7 " 0.5 (stat)-0.4+0.5 (syst) " 0.4 (theo) " 0.2 (lumi) pb, for both Z bosons produced in the mass range 60