Download or read book Measurement of Inclusive Jet Cross Sections in Z gamma e e Jets Production in Ppbar Collisions at S 1 2 written by and published by . This book was released on 2008 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Ph. D. thesis presents the measurement of inclusive jet cross sections in Z/[gamma]* 2!ee− events using 1.7 fb−1 of data collected by the upgraded CDF detector during the Run II of the Tevatron. The Midpoint cone algorithm is used to search for jets in the events after identifying the presence of a Z/[gamma]* boson through the reconstruction of its decay products. The measurements are compared to next-to-LO (NLO) pQCD predictions for events with one and two jets in the final state. The perturbative predictions are corrected for the contributions of non-perturbative processes, like the underlying event and the fragmentation of the partons into jets of hadrons. These processes are not described by perturbation theory and must be estimated from phenomenological models. In this thesis, a number of measurements are performed to test different models of underlying event and hadronization implemented in LO plus parton shower Monte Carlo generator programs. Chapter 2 is devoted to the description of the theory of strong interactions and jet phenomenology at hadron colliders. Chapter 3 contains the description of the Tevatron collider and the CDF detector. The analysis is described in detail in Chapter 4. Chapter 5 shows the measurement of those observables sensitive to non-perturbative effects compared to the predictions from several Monte Carlo programs. Chapter 6 discusses the final results and the comparison with theoretical expectations. Finally, Chapter 7 is devoted to the conclusions.
Download or read book Measurement of Inclusive Jet Cross sections in Z gamma E E Jets Production in P Anti p Collisions at S 1 2 written by and published by . This book was released on 2007 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Inclusive jet cross sections in Z/[gamma]* events, with Z/[gamma]* decaying into an electron-positron pair, are measured as a function of jet transverse momentum and jet multiplicity in p{bar p} collisions at √s - 1.96 TeV with the upgraded Collider Detector at Fermilab in Run II, based on an integrated luminosity of 1.7 fb−1. The measurements cover the rapidity region
Download or read book Measurement of Inclusive Jet Cross Sections in Z u2192 e e Jets Production in P bar p Collisions at u221A s written by and published by . This book was released on 2008 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Ph.D. thesis presents the measurement of inclusive jet cross sections in Z/?*→ e+e- events using 1.7 fb-1 of data collected by the upgraded CDF detector during the Run II of the Tevatron. The Midpoint cone algorithm is used to search for jets in the events after identifying the presence of a Z/?* boson through the reconstruction of its decay products. The measurements are compared to next-to-LO (NLO) pQCD predictions for events with one and two jets in the final state. The perturbative predictions are corrected for the contributions of non-perturbative processes, like the underlying event and the fragmentation of the partons into jets of hadrons. These processes are not described by perturbation theory and must be estimated from phenomenological models. In this thesis, a number of measurements are performed to test different models of underlying event and hadronization implemented in LO plus parton shower Monte Carlo generator programs. Chapter 2 is devoted to the description of the theory of strong interactions and jet phenomenology at hadron colliders. Chapter 3 contains the description of the Tevatron collider and the CDF detector. The analysis is described in detail in Chapter 4. Chapter 5 shows the measurement of those observables sensitive to non-perturbative effects compared to the predictions from several Monte Carlo programs. Chapter 6 discusses the final results and the comparison with theoretical expectations. Finally, Chapter 7 is devoted to the conclusions.
Download or read book Measurement of Inclusive Jet Cross Sections in Z e e Jets Production in Pp Collisions at s written by Oriol Saltó Bauzà and published by . This book was released on 2008 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of the Inclusive Jet Cross Section Using the K T Algorithm in P Anti p Collisions at S 1 2 written by and published by . This book was released on 2005 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors report on a measurement of the inclusive jet production cross section in p{bar p} collisions at √s = 1.96 TeV using data collected with the upgraded Collider Detector at Fermilab in Run II (CDF II) corresponding to an integrated luminosity of 385 pb−1. Jets are reconstructed using the k{sub T} algorithm. The measurement is carried out for jets with rapidity 0.1
Download or read book Measurement of Z gamma B jet Production Cross Section in p bar p Collisions at sqrt s written by and published by . This book was released on 2012 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt: Processes at hadron colliders, such as the production of jets, are described by the Quantum Chromodynamics theory (QCD). Precise descriptions of processes involving jets in association with a vector boson have nowadays large relevance as they represent irreducible background to other Standard Model (SM) processes and searches for new physics. The experimental study and understanding of the b-jet production in association with a Z boson are crucial for many reasons. For one side, it is the most important background for a light Higgs boson decaying into a bottom-antibottom quark pair and produced in the ZH mode. This is one of the most promising channels for the Higgs search at Tevatron in particular since the latest results have excluded the high mass region (MH> 127 GeV/c2). For another side the signature of b-jets and a Z boson is also background to new physics searches, such as supersymmetry, where a large coupling of the Higgs boson to bottom quarks is allowed. The produ ction cross section measurement of b-jets in events with a Z boson has already been performed at hadron colliders, at the Tevatron by CDF and D0 experiments and are now pursued at the LHC by ATLAS and CMS. In particular the CDF measurement was performed with only 2 fb-1 and was limited by the statistical uncertainty. This PhD thesis presents a new measurement of the $Z/\gamma^* + b$-jet production cross section using the complete dataset collected by CDF during the Run II. $Z/\gamma^*$ bosons are selected in the electron and muon decay modes and are required to have 66
Download or read book Measurements of Differential Cross Sections of Z gamma jets X Events in Proton Anti proton Collisions at S 1 2 written by and published by . This book was released on 2009 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present cross section measurements for Z/[gamma]* + jets + X production, differential in the transverse momenta of the three leading jets. The data sample was collected with the D0 detector at the Fermilab Tevatron p{bar p} collider at a center-of-mass energy of 1.96 TeV and corresponds to an integrated luminosity of 1 fb−1. Leading and next-to-leading order perturbative QCD predictions are compared with the measurements, and agreement is found within the theoretical and experimental uncertainties. We also make comparisons with the predictions of four event generators. Two parton-shower-based generators show significant shape and normalization differences with respect to the data. In contrast, two generators combining tree-level matrix elements with a parton shower give a reasonable description of the shapes observed in data, but the predicted normalizations show significant differences with respect to the data, reflecting large scale uncertainties. For specific choices of scales, the normalizations for either generator can be made to agree with the measurements.
Download or read book Measurements of Jet Multiplicity and Differential Production Cross Sections of Z Jets Events in Proton proton Collisions at u221A s written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of differential cross sections are presented for the production of a Z boson and at least one hadronic jet in proton-proton collisions at √s = 7 TeV, recorded by the CMS detector, using a data sample corresponding to an integrated luminosity of 4.9 inverse femtobarns. The jet multiplicity distribution is measured for up to six jets. The differential cross sections are measured as a function of jet transverse momentum and pseudorapidity for the four highest transverse momentum jets. The distribution of the scalar sum of jet transverse momenta is also measured as a function of the jet multiplicity. The measurements are compared with theoretical predictions at leading and next-to-leading order in perturbative QCD.
Download or read book Inclusive Jet Cross Section at CDF written by and published by . This book was released on 2005 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: This contribution reports on preliminary measurements of the inclusive jet production cross section in p{bar p} collisions at √s = 1.96 TeV using data collected with CDF corresponding to an integrated luminosity of 385 pb−1. Two analyzes are presented: one uses the longitudinally invariant k{sub T} algorithm to reconstruct the jets, the other uses the midpoint algorithm. Both are limited to jets with rapidity in the range 0.1
Download or read book Measurement of the Ratio of Inclusive Cross Sections p p Z b jet p p Z jet in the Dilepton Final States written by and published by . This book was released on 2010 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: The inclusive production of b-jets with a Z boson is an important background to searches for the Higgs boson in associated ZH → llb{bar b} production at the Fermilab Tevatron collider. This thesis describes the most precise measurement to date of the ratio of inclusive cross sections [sigma](p{bar p} → Z + b-jet)/[sigma](p{bar p} → Z + jet) when a Z boson decays into two electrons or muons. The measurement uses a data sample from p{bar p} collisions at the center of mass energy √s = 1.96 TeV corresponding to an integrated luminosity of 4.2 fb−1 collected by the D0 detector. The measured ratio [sigma](Z + b-jet)/[sigma](Z + jet) is 0.0187 ± 0.0021(stat) ± 0.0015(syst) for jets with transverse momentum p{sub T} > 20 GeV and pseudorapidity.
Download or read book Z Jets Cross Section Ratio Measurements written by and published by . This book was released on 2007 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a study of events with Z bosons and jets produced at the Fermilab Tevatron Collider in p{bar p} collisions at a center of mass energy of 1.96 TeV. The data sample consists of nearly 14,000 Z/[gamma]* 2!ee− candidates corresponding to the integrated luminosity of 340 pb−1 collected using the D0 detector. Ratios of the Z/[gamma]* + d"n jet cross sections to the total inclusive Z/[gamma]* cross section have been measured for n = 1 to 4 jet events. Our measurements are found to be in good agreement with a next-to-leading order QCD calculation and with a tree-level QCD prediction with parton shower simulation and hadronization.
Download or read book Measurement of Cross Sections for B Jet Production in Events with a Z Boson in P anti p Collisions at S 1 2 written by and published by . This book was released on 2008 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: A measurement of the b jet production cross section is presented for events containing a Z boson produced in p{bar p} collisions at √s = 1.96 TeV, using data corresponding to an integrated luminosity of 2 fb−1 collected by the CDF II detector at the Tevatron. Z bosons are selected in the electron and muon decay modes. Jets are considered with transverse energy E{sub T} > 20 GeV and pseudorapidity.
Download or read book Measurement of the Ratio of Inclusive Cross Sections p bar p u2192 Z b jet p bar p u2192 Z jet in the Dilepton Final States written by and published by . This book was released on 2010 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: The inclusive production of b-jets with a Z boson is an important background to searches for the Higgs boson in associated ZH → llb$ar{b}$ production at the Fermilab Tevatron collider. This thesis describes the most precise measurement to date of the ratio of inclusive cross sections ?(p$ar{p}$ → Z + b-jet)/?(p$ar{p}$ → Z + jet) when a Z boson decays into two electrons or muons. The measurement uses a data sample from p$ar{p}$ collisions at the center of mass energy √s = 1.96 TeV corresponding to an integrated luminosity of 4.2 fb-1 collected by the D0 detector. The measured ratio ?(Z + b-jet)/?(Z + jet) is 0.0187 ± 0.0021(stat) ± 0.0015(syst) for jets with transverse momentum pT > 20 GeV and pseudorapidity.
Download or read book Measurement of Differential Production Cross sections for a Z Boson in Association with B jets in 7 TeV Proton proton Collisions with the ATLAS Detector written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We report measurements of differential production cross-sections of a Z boson in association with b-jets in pp collisions at √ s = 7 TeV. The data analysed correspond to an integrated luminosity of 4.6 fb-1 recorded with the ATLAS detector at the Large Hadron Collider. Particle-level cross-sections are determined for events with a Z boson decaying into an electron or muon pair, and containing b-jets. For events with at least one b-jet, the cross-section is presented as a function of the Z boson transverse momentum and rapidity, together with the inclusive b-jet cross-section as a function of b-jet transverse momentum, rapidity and angular separations between the b-jet and the Z boson. For events with at least two b-jets, the cross-section is determined as a function of the invariant mass and angular separation of the two highest transverse momentum b-jets, and as a function of the Z boson transverse momentum and rapidity. Lastly, results are compared to leading-order and next-to-leading-order perturbative QCD calculations.
Download or read book Measurement of the Production Cross Section of Jets in Association with a Z Boson in 8 TeV Proton proton Collisions with the ATLAS Detector written by Rodger Mantifel and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "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." --
Download or read book Measurements of Differential Cross Sections of Z gamma jets X Events in Proton Anti proton Collisions at S written by and published by . This book was released on 2009 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present cross section measurements for Z/?* + jets + X production, differential in the transverse momenta of the three leading jets. The data sample was collected with the D0 detector at the Fermilab Tevatron p{bar p} collider at a center-of-mass energy of 1.96 TeV and corresponds to an integrated luminosity of 1 fb−1. Leading and next-to-leading order perturbative QCD predictions are compared with the measurements, and agreement is found within the theoretical and experimental uncertainties. We also make comparisons with the predictions of four event generators. Two parton-shower-based generators show significant shape and normalization differences with respect to the data. In contrast, two generators combining tree-level matrix elements with a parton shower give a reasonable description of the shapes observed in data, but the predicted normalizations show significant differences with respect to the data, reflecting large scale uncertainties. For specific choices of scales, the normalizations for either generator can be made to agree with the measurements.
Download or read book Measurements of Differential Z gamma jet X Cross Sections with the D0 Detector written by and published by . This book was released on 2009 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present measurements of differential cross sections in inclusive Z/[gamma]* plus jet production in a data sample of 1 fb−1 collected with the D0 detector in proton antiproton collisions at √s = 1.96 TeV. Measured variables include the Z/[gamma]* transverse momentum (p{sub T}{sup Z}) and rapidity (y{sup Z}), the leading jet transverse momentum (p{sub T}{sup jet}) and rapidity (y{sup jet}), as well as various angles of the Z+jet system. We compare the results to different Monte Carlo event generators and next-to-leading order perturbative QCD (NLO pQCD) predictions, with non-perturbative corrections applied.
