Physics with Jets in Association with a Z Boson in Pp-collisions with the ATLAS Detector at the Large Hadron Collider

Physics with Jets in Association with a Z Boson in Pp-collisions with the ATLAS Detector at the Large Hadron Collider PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 240

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Book Description
This thesis presents the measurements of the production cross section of jets in association with a Z boson in pp-collisions at √s = 7 TeV with an integrated luminosity of ∫Ldt = 36-1 and ∫Ldt = 4.6 fb-1 recorded by the ATLAS experiment at the Large Hadron Collider in Geneva. Inclusive and differential Z(→e+e-) + jets cross sections are measured for jets with a transverse momentum pT(jet) > 30 GeV and rapidity |y(jet)|

Physics with Jets in Association with a Z Boson in Pp-collisions with the ATLAS Detector at the Large Hadron Collider

Physics with Jets in Association with a Z Boson in Pp-collisions with the ATLAS Detector at the Large Hadron Collider PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 240

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Book Description
This thesis presents the measurements of the production cross section of jets in association with a Z boson in pp-collisions at √s = 7 TeV with an integrated luminosity of ∫Ldt = 36-1 and ∫Ldt = 4.6 fb-1 recorded by the ATLAS experiment at the Large Hadron Collider in Geneva. Inclusive and differential Z(→e+e-) + jets cross sections are measured for jets with a transverse momentum pT(jet) > 30 GeV and rapidity |y(jet)|

Measurement of the Production Cross Section of Jets in Association with a Z Boson in 8 TeV Proton-proton Collisions with the ATLAS Detector

Measurement of the Production Cross Section of Jets in Association with a Z Boson in 8 TeV Proton-proton Collisions with the ATLAS Detector PDF Author: Rodger Mantifel
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
"This thesis presents the measurement of the production cross sections of jets in association with a Z boson in proton-proton collisions at √s = 8 TeV with an integrated luminosity of 20.3 fb−1 recorded by the ATLAS experiment at the Large Hadron Collider at CERN. Inclusive and differential Z/[gamma]∗(→ e+e−)+jets cross sections are measured for jets with a transversemomentum pT(jet) > 30 GeV and rapidity |y(jet)| 4.4. Z boson candidates are identified by their decay into electron pairs. In order to stringently probe the modelling of Z/[gamma]∗+jets production by Monte Carlo generators in regions of high-pT phase space typical for Higgs boson decay and searches for new physics, events with high-pT final states are investigated. High-pT final states are defined as events with either pT(Z) 300 GeV or pT(leading jet) > 300 GeV. A set of four observables, sensitive to the topology of the event, are measured for the standard event selection as well as in the regions of high-pT phase space. The results from data are unfolded to particle level and compared to calculations of the matrix element from Monte Carlo generators Alpgen+Pythia and Sherpa interfaced to a parton shower. The results show that Sherpa tends to model Z/[gamma]∗+jets production in high-pT regions of phase space much better than Alpgen+Pythia." --

Search for New Physics in Mono-jet Final States in pp Collisions

Search for New Physics in Mono-jet Final States in pp Collisions PDF Author: Giuliano Gustavino
Publisher: Springer
ISBN: 3319588710
Category : Science
Languages : en
Pages : 245

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Book Description
This thesis provides a detailed and comprehensive description of the search for New Physics at the Large Hadron Collider (LHC) in the mono-jet final state, using the first 3.2 fb-1 of data collected at the centre of mass energy of colliding protons of 13~TeV recorded in the ATLAS experiment at LHC. The results are interpreted as limits in different theoretical contexts such as compressed supersymmetric models, theories that foresee extra-spatial dimensions and in the dark matter scenario. In the latter the limits are then compared with those obtained by other ATLAS analyses and by experiments based on completely different experimental techniques, highlighting the role of the mono-jet results in the context of dark matter searches.Lastly, a set of possible analysis improvements are proposed to reduce the main uncertainties that affect the signal region and to increase the discovery potential by further exploiting the information on the final state.

Study of Jets Production Association with a Z Boson in Pp Collision at 7 and 8 TeV with the CMS Detector

Study of Jets Production Association with a Z Boson in Pp Collision at 7 and 8 TeV with the CMS Detector PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 127

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Book Description
This study presents the measurement of the rapidity distributions in events containing a Z boson and a jet in proton-proton collisions at a center-of-mass energy of 7 TeV. The data correspond to an integrated luminosity of approximately 5 fb-11, recorded by the CMS detector at the Large Hadron Collider (LHC). The measured angular distributions are compared with the predictions from next-to-leading order perturbative QCD calculations and two generator programs that combine tree-level matrix element calculations with parton showers. We also present a measurement of jet production rates in association with a Z boson using data recorded at a center-of-mass energy of 8 TeV and with an integrated luminosity of 19.8 fb-1. This measurement provides a stringent test of perturbative QCD calculations, and the result is compared with predictions from theoretical calculations.

Electroweak Physics at the Large Hadron Collider with the ATLAS Detector

Electroweak Physics at the Large Hadron Collider with the ATLAS Detector PDF Author: Elodie Resseguie
Publisher: Springer Nature
ISBN: 3030570169
Category : Science
Languages : en
Pages : 336

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Book Description
This thesis discusses searches for electroweakly produced supersymmetric partners of the gauge and the Higgs bosons (gauginos and higgsinos) decaying to multiple leptons, using pp collisions at sqrt(s) = 13 TeV. The thesis presents an in-depth study of multiple searches, as well as the first 13 TeV cross section measurement for the dominant background in these searches, WZ production. Two searches were performed using 36.1/fb of data: the gaugino search, which makes use of a novel kinematic variable, and the higgsino search, which produced the first higgsino limits at the LHC. A search using 139/fb of data makes use of a new technique developed in this thesis to cross check an excess of data above the background expectation in a search using a Recursive Jigsaw Reconstruction technique. None of the searches showed a significant excess of data, and limits were expanded with respect to previous results. These searches will benefit from the addition of luminosity during HL-LHC; however, the current detector will not be able to withstand the increase in radiation. Electronics for the detector upgrade are tested and irradiated to ensure their performance.

Third generation SUSY and t ̄t +Z production

Third generation SUSY and t ̄t +Z production PDF Author: Josh McFayden
Publisher: Springer
ISBN: 3319071912
Category : Science
Languages : en
Pages : 190

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Book Description
This thesis describes searches for new particles predicted by the super symmetry (SUSY) theory, a theory extending beyond the current Standard Model of particle physics, using the ATLAS detector at the CERN Large Hadron Collider. The thesis focuses on searches for stop and sbottom squarks, the SUSY partners of the top and bottom quarks, which are expected to be lighter than the partners of the first and second generation quarks and therefore good candidates for the first evidence of SUSY. It describes novel techniques for estimating and rejecting the Standard-Model backgrounds to searches for these particles. It also includes an independent analysis seeking to constrain the Standard Model ttZ background process, which also represents the first ATLAS search for this rare process at the LHC. The stop squark analysis described, with substantial leading contributions from the author, is the first search for these particles at the LHC to use the jets plus missing transverse energy plus 0-lepton signature and provides the world's best limits on the stop mass for light neutralino LSPs. All in all, the thesis describes three different world-leading analyses in both Standard Model and SUSY physics and therefore represents a major contribution to the field.

Search for Dark Matter Produced in Association with a Higgs Boson Decaying to Two Bottom Quarks at ATLAS

Search for Dark Matter Produced in Association with a Higgs Boson Decaying to Two Bottom Quarks at ATLAS PDF Author: Yangyang Cheng
Publisher: Springer
ISBN: 331944218X
Category : Science
Languages : en
Pages : 183

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Book Description
This thesis reports on the search for dark matter in data taken with the ATLAS detector at CERN’s Large Hadron Collider (LHC). The identification of dark matter and the determination of its properties are among the highest priorities in elementary particle physics and cosmology. The most likely candidate, a weakly interacting massive particle, could be produced in the high energy proton-proton collisions at the LHC. The analysis presented here is unique in looking for dark matter produced together with a Higgs boson that decays into its dominant decay mode, a pair of b quarks. If dark matter were seen in this mode, we would learn directly about the production mechanism because of the presence of the Higgs boson. This thesis develops the search technique and presents the most stringent production limit to date.

Electroweak Physics at the LHC

Electroweak Physics at the LHC PDF Author: Matthias U. Mozer
Publisher: Springer
ISBN: 3319303813
Category : Science
Languages : en
Pages : 121

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Book Description
The book discusses the recent experimental results obtained at the LHC that involve electroweak bosons. The results are placed into an appropriate theoretical and historical context. The work pays special attention to the rising subject of hadronically decaying bosons with high boosts, documenting the state-of-the-art identification techniques and highlighting typical results. The text is not limited to electroweak physics in the strict sense, but also discusses the use of electroweak vector-bosons as tool in the study of other subjects in particle physics, such as determinations of the proton structure or the search for new exotic particles. The book is particularly well suited for graduate students, starting their thesis work on topics that involve electroweak bosons, as the book provides a comprehensive description of phenomena observable at current accelerators as well as a summary of the most relevant experimental techniques.

High Jet Multiplicity Physics at the LHC

High Jet Multiplicity Physics at the LHC PDF Author: Mireia Crispín Ortuzar
Publisher: Springer
ISBN: 3319434616
Category : Science
Languages : en
Pages : 194

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Book Description
This book describes research in two different areas of state-of-the-art hadron collider physics, both of which are of central importance in the field of particle physics. The first part of the book focuses on the search for supersymmetric particles called gluinos. The book subsequently presents a set of precision measurements of “multi-jet” collision events, which involve large numbers of newly created particles, and are among the dominant processes at the Large Hadron Collider (LHC). Now that a Higgs boson has been discovered at the LHC, the existence (or non-existence) of supersymmetric particles is of the utmost interest and significance, both theoretically and experimentally. In addition, multi-jet collision events are an important background process for a wide range of analyses, including searches for supersymmetry.

Advances in Jet Substructure at the LHC

Advances in Jet Substructure at the LHC PDF Author: Roman Kogler
Publisher: Springer Nature
ISBN: 3030728587
Category : Science
Languages : en
Pages : 287

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Book Description
This book introduces the reader to the field of jet substructure, starting from the basic considerations for capturing decays of boosted particles in individual jets, to explaining state-of-the-art techniques. Jet substructure methods have become ubiquitous in data analyses at the LHC, with diverse applications stemming from the abundance of jets in proton-proton collisions, the presence of pileup and multiple interactions, and the need to reconstruct and identify decays of highly-Lorentz boosted particles. The last decade has seen a vast increase in our knowledge of all aspects of the field, with a proliferation of new jet substructure algorithms, calculations and measurements which are presented in this book. Recent developments and algorithms are described and put into the larger experimental context. Their usefulness and application are shown in many demonstrative examples and the phenomenological and experimental effects influencing their performance are discussed. A comprehensive overview is given of measurements and searches for new phenomena performed by the ATLAS and CMS Collaborations. This book shows the impressive versatility of jet substructure methods at the LHC.