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Precision measurement of and search for dark matter in the transverse momentum spectra of Z bosons

A measurement of the differential Z boson production cross section in proton-proton collisions is presented. It furnishes a precision test of the Standard Model, and constrains the parton distribution functions of the proton. Moreover, it is a building block for future measurements of the mass of th...

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Autor principal: Hsu, Dylan George
Lenguaje:eng
Publicado: 2019
Materias:
Acceso en línea:http://cds.cern.ch/record/2725960
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author Hsu, Dylan George
author_facet Hsu, Dylan George
author_sort Hsu, Dylan George
collection CERN
description A measurement of the differential Z boson production cross section in proton-proton collisions is presented. It furnishes a precision test of the Standard Model, and constrains the parton distribution functions of the proton. Moreover, it is a building block for future measurements of the mass of the W$^{\pm}$ boson. A study of the efficiency of lepton identification algorithms is performed which drives the precision of the measurement at lower values of transverse momentum. In tandem, a search for new physics in events with a Z boson produced in association with large missing transverse momentum is presented. The results of this search are interpreted in the context of several dark matter models: generic spin-0 or spin-1 mediators, invisible decays of a Higgs-like boson, unparticles, and large extra spatial dimensions. A multivariate analysis was developed to enhance the sensitivity of the invisible Higgs interpretation. The theoretical uncertainty on the irreducible background from electroweak diboson processes is constrained by emulating the missing energy using pure control samples in the fully leptonic final states. The data were collected with the Compact Muon Solenoid detector at the Large Hadron Collider and correspond to an integrated luminosity of 35.9 fb$^{-1}$. No significant deviations from the Standard Model are found.
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spelling oai-inspirehep.net-17940402021-03-01T10:43:53Zhttp://cds.cern.ch/record/2725960engHsu, Dylan GeorgePrecision measurement of and search for dark matter in the transverse momentum spectra of Z bosonsParticle Physics - ExperimentA measurement of the differential Z boson production cross section in proton-proton collisions is presented. It furnishes a precision test of the Standard Model, and constrains the parton distribution functions of the proton. Moreover, it is a building block for future measurements of the mass of the W$^{\pm}$ boson. A study of the efficiency of lepton identification algorithms is performed which drives the precision of the measurement at lower values of transverse momentum. In tandem, a search for new physics in events with a Z boson produced in association with large missing transverse momentum is presented. The results of this search are interpreted in the context of several dark matter models: generic spin-0 or spin-1 mediators, invisible decays of a Higgs-like boson, unparticles, and large extra spatial dimensions. A multivariate analysis was developed to enhance the sensitivity of the invisible Higgs interpretation. The theoretical uncertainty on the irreducible background from electroweak diboson processes is constrained by emulating the missing energy using pure control samples in the fully leptonic final states. The data were collected with the Compact Muon Solenoid detector at the Large Hadron Collider and correspond to an integrated luminosity of 35.9 fb$^{-1}$. No significant deviations from the Standard Model are found.CERN-THESIS-2019-378oai:inspirehep.net:17940402019
spellingShingle Particle Physics - Experiment
Hsu, Dylan George
Precision measurement of and search for dark matter in the transverse momentum spectra of Z bosons
title Precision measurement of and search for dark matter in the transverse momentum spectra of Z bosons
title_full Precision measurement of and search for dark matter in the transverse momentum spectra of Z bosons
title_fullStr Precision measurement of and search for dark matter in the transverse momentum spectra of Z bosons
title_full_unstemmed Precision measurement of and search for dark matter in the transverse momentum spectra of Z bosons
title_short Precision measurement of and search for dark matter in the transverse momentum spectra of Z bosons
title_sort precision measurement of and search for dark matter in the transverse momentum spectra of z bosons
topic Particle Physics - Experiment
url http://cds.cern.ch/record/2725960
work_keys_str_mv AT hsudylangeorge precisionmeasurementofandsearchfordarkmatterinthetransversemomentumspectraofzbosons