Download or read book Measurement of the Z Production Cross Section in Pp Collisions at 8 TeV and Search for Anomalous Triple Gauge Boson Couplings written by and published by . This book was released on 2015 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: The cross section for the production of Z? in proton-proton collisions at 8 TeV is measured based on data collected by the CMS experiment at the LHC corresponding to an integrated luminosity of 19.5 fb-1. Events with an oppositely-charged pair of muons or electrons together with an isolated photon are selected. Furthermore, the differential cross section as a function of the photon transverse momentum is measured inclusively and exclusively, where the exclusive selection applies a veto on central jets. These observed cross sections are compatible with the expectations of next-to-next-to-leading-order quantum chromodynamics. As a result, limits on anomalous triple gauge couplings of ZZ? and Z?? are set that improve on previous experimental results obtained with the charged lepton decay modes of the Z boson.

Download or read book Measurement of the Z gamma Production Cross Section in Pp Collisions at 8 TeV and Search for Anomalous Triple Gauge Boson Couplings written by and published by . This book was released on 2015 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: The cross section for the production of Z[gamma] in proton-proton collisions at 8 TeV is measured based on data collected by the CMS experiment at the LHC corresponding to an integrated luminosity of 19.5 fb-1. Events with an oppositely-charged pair of muons or electrons together with an isolated photon are selected. Furthermore, the differential cross section as a function of the photon transverse momentum is measured inclusively and exclusively, where the exclusive selection applies a veto on central jets. These observed cross sections are compatible with the expectations of next-to-next-to-leading-order quantum chromodynamics. As a result, limits on anomalous triple gauge couplings of ZZ[gamma] and Z[gamma][gamma] are set that improve on previous experimental results obtained with the charged lepton decay modes of the Z boson.

Download or read book Measurements of Z and Z Production in Pp Collisions at S written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The production of Z bosons with one or two isolated high-energy photons is studied using pp collisions at √s=8 TeV. The analyses use a data sample with an integrated luminosity of 20.3 fb-1 collected by the ATLAS detector during the 2012 LHC data taking. The Z? and Z?? production cross sections are measured with leptonic (e+e-, ?+?-, ?????????) decays of the Z boson, in extended fiducial regions defined in terms of the lepton and photon acceptance. They are then compared to cross-section predictions from the Standard Model, where the sources of the photons are radiation off initial-state quarks and radiative Z-boson decay to charged leptons, and from fragmentation of final-state quarks and gluons into photons. The yields of events with photon transverse energy ET > 250 GeV from l+l-? events and with ET > 400 GeV from ?????????? events are used to search for anomalous triple gauge-boson couplings ZZ? and Z??. The yields of events with diphoton invariant mass m?? > 200 GeV from l+l-?? events and with m?? > 300 GeV from ??????????? events are used to search for anomalous quartic gauge-boson couplings ZZ?? and Z???. As a result, no deviations from Standard Model predictions are observed and limits are placed on parameters used to describe anomalous triple and quartic gauge-boson couplings.

Download or read book Measurements of W Z Production Cross Sections in Pp Collisions at S written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This study presents measurements of W±Z production in pp collisions at a center-of-mass energy of 8 TeV. The gauge bosons are reconstructed using their leptonic decay modes into electrons and muons. The data were collected in 2012 by the ATLAS experiment at the Large Hadron Collider and correspond to an integrated luminosity of 20.3 fb-1. The measured inclusive cross section in the detector fiducial region is ?W±Z→l'?ll = 35.1 ± 0.9(stat) ± 0.8(sys) ± 0.8(lumi) fb, for one leptonic decay channel. In comparison, the next-to-leading-order Standard Model expectation is 30.0 ± 2.1 fb. Cross sections for W+Z and W-Z production and their ratio are presented as well as differential cross sections for several kinematic observables. Limits on anomalous triple gauge boson couplings are derived from the transverse mass spectrum of the W±Z system. From the analysis of events with a W and a Z boson associated with two or more forward jets an upper limit at 95% confidence level on the W±Z scattering cross section of 0.63 fb, for each leptonic decay channel, is established, while the Standard Model prediction at next-to-leading order is 0.13 ± 0.01 fb. Limits on anomalous quartic gauge boson couplings are also extracted.

Download or read book Measurement of the Pp u2192 ZZ Production Cross Section and Constraints on Anomalous Triple Gauge Couplings in Four lepton Final States at u221A s written by and published by . This book was released on 2014 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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

Download or read book Measurement of the Pp 2 ZZ Production Cross Section and Constraints on Anomalous Triple Gauge Couplings in Four lepton Final States at arrow written by and published by . This book was released on 2014 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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

Download or read book Evidence of W Production in Pp Collisions at S written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Here we report evidence of triple gauge boson production pp→W(l?)??+X, which is accessible for the first time with the 8 TeV LHC data set. The fiducial cross section for this process is measured in a data sample corresponding to an integrated luminosity of 20.3 fb−1, collected by the ATLAS detector in 2012. Events are selected using the W boson decay to e? or ?? as well as requiring two isolated photons. The measured cross section is used to set limits on anomalous quartic gauge couplings in the high diphoton mass region.

Download or read book Measurements of ZZ Production Cross Section Using Four lepton Events and Constraints on Anomalous Triple Gauge Couplings at squareroot s written by Usama Hussain and published by . This book was released on 2020 with total page 219 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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

Download or read book Measurement of the ZZ Production Cross Section and Limits on Anomalous Neutral Triple Gauge Couplings with the ATLAS Detector written by Nicholas Charles Edwards and published by . This book was released on 2013 with total page 251 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Measurement of W Boson Pair Production in Pp Collisions at Sqrt s written by Philip Sommer and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Zusammenfassung: In this thesis, measurements of the W boson pair production cross section in proton-proton collisions at a centre-of-mass energy of 8 TeV are presented. A dataset corresponding to an integrated luminosity of 22.3 /fb recorded by the ATLAS experiment in the year 2012 is used. The W bosons are identified by their decay products of exactly two leptons with opposite electrical charge, electrons or muons, and missing transverse momentum induced by their corresponding neutrinos. First, a measurement restricted to final states without hadronic jets is presented and differential fiducial cross sections, total cross sections and limits on anomalous triple gauge boson couplings are obtained. A second measurement of the fiducial cross section in association with exactly one hadronic jet is presented. The ratio of fiducial cross sections for different jet multiplicities is reported and the combined fiducial cross section is extrapolated to the total phase space.

Download or read book Measurement of Z Production and Search for Anomalous Triple Gauge Couplings in Proton antiproton Collisions at u221A S written by and published by . This book was released on 2008 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt: The author presents a measurement of p$ar{p}$ → Z? + X → e+e-? + X production using proton-antiproton collisions data collected at the Collider Detector at Fermilab at a center of mass energy of 1.96 TeV. Z? production provides a direct test of the triple neutral gauge couplings. A measurement of Z? production cross section and search for anomalous ZZ? and Z?? couplings are presented. The data presented are from 1.1 fb-1 of p$ar{p}$ integrated luminosity collected at the CDF Detector. Electrons from Z decays are selected with Et > 20 Gev. Photons (Et > 7 GeV) are required to be well-separated from the electrons. There are 390 ee? candidate events found with 1.1 fb-1 of data, compared to the SM prediction of 375.3 ± 25.2 events. The Standard Model prediction for the cross section for p$ar{p}$ → e+e-? + X production at √s = 1.96 TeV is 4.5 ± 0.4 pb. The measured cross section is 4.7 ± 0.6 pb. The cross section and kinematic distributions of the ee? events are in good agreement with theoretical predictions. Limits on the ZZ? and Z?? couplings are extracted using the photon Et distribution of ee? events with mee? > 100 GeV/c2. These are the first limits measured using CDF Run II data. These limits provide important test of the interaction of the photon and the Z boson.

Download or read book Electroweak Physics at the LHC written by Matthias U. Mozer and published by Springer. This book was released on 2016-03-24 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book A Measurement of the W Z Production Cross Section and Limits on Anomalous Trilinear Gauge Couplings in Proton proton Collisions at s written by Advait Neel Nagarkar and published by . This book was released on 2012 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt: I present a measurement of the W±Z production cross section in the leptonic final states in pp collisions at √s = 7 TeV and limits on anomalous trilinear gauge couplings, using 4.64 fb-1 of data collected using the ATLAS experiment at the LHC. The production cross section has been determined to be 19.0+1.4-1.3(stat.)±0.9(syst.)±0.4(lumi.) pb, in agreement with the Standard Model (SM) expectation of 17.6+1.1-1.0 pb. A search for anomalous trilinear gauge couplings has been conducted and limits have been set at the 95% confidence level; the result is consistent with the SM couplings.

Download or read book Measurement of the Proton proton to ZZX Cross Section at a Center of Mass Energy of 8 TeV written by Hayes Merritt and published by . This book was released on 2013 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: A measurement of ZZ production in the 4l channel with pp collisions at sqrt(s)=8 TeV using the full 2012 dataset amounting to an integrated luminosity of 20 fb-1 collected by the ATLAS experiment is presented in this paper. An event is selected when exactly four reconstructed, isolated leptons are found in the final state. Each pair of leptons reconstructed to form a Z boson must have opposite sign and same flavor and have an invariant mass between 66 and 116 GeV. The background contribution is determined using a data-driven technique due to limited Monte Carlo statistics. Limits on the f_4^gamma, f_4^Z,f_5^gamma, f_5^Z anomalous triple gauge couplings are also presented.

Download or read book Measurement of Cross Section Times Branching Ratio for W Boson Photon and Z Boson Photon and Search for Anomalous W Boson photon and Z Boson photon Couplings at 1 8 TeV written by Mark Frank Vondracek and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of the production cross section times branching ratio for $W + \gamma$ and $Z + \gamma$ processes, where the W decays into a muon and neutrino and the Z decays into a muon pair, have been made from the analysis of 18.6 $\pm$ 0.7 $pb\sp{-1}$ of high-$P\sb{T}$ muon data from proton-antiproton (pp) collisions. The data were collected with the Collider Detector at Fermilab (CDF) during the 1992-93 run. In a search for central photons ($\vert\eta\vert\

Download or read book A Measurement of the Z Gamma Cross Section and Limits on Anomalous Triple Gauge Couplings at Square Root of S written by and published by . This book was released on 2012 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study of the properties of the Z$\gamma$ diboson system is presented using 5.0 fb$^{-1}$ of proton-proton collision data from the LHC using the CMS detector. The pp $\rightarrow Z(\rightarrow\mu \mu) \gamma$ and pp $\rightarrow Z(\rightarrow e e) \gamma$ production cross sections are measured within the fiducial volume of CMS with a combined measurement of $\sigma_{\ell\ell\gamma} = 5.33 \pm 0.08 ~\text{(stat.)} \pm 0.25 ~\text{(syst.)} \pm 0.12 ~\text{(lumi.)}$ pb that is in good agreement with Standard Model predictions. Upper limits on the neutral anomalous triple gauge couplings set are the most stringent limits on these couplings to date, with allowed regions: $-0.010

Download or read book Measurement of the WZ rightarrow ell nu ell ell Cross Section and Limits on Anomalous Triple Gauge Couplings in p bar p Collisions at sqrt s written by and published by . This book was released on 2010 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: The standard model (SM) of particle physics has been extensively tested in the past three decades and is found to be in excellent agreement with experimental observations. It is widely assumed, however, that the SM is only a low energy approximation of a more general theory. Therefore, any significant deviation from the SM predictions yields information on the nature of a more fundamental theory. Production of WZ pairs is the least studied diboson process within the SM, as it is a charged final state and can only be produced at hadron colliders. A detailed study of this process probes the electroweak sector of the SM. In addition, searches for new phenomena in the production of heavy gauge boson pairs are interesting, as many extensions of the SM predict 1-4 additional heavy gauge bosons that can decay into a WZ boson pairs.