Download or read book Measurement of the Forward backward Asymmetry of Electron and Muon Pair production in Pp Collisions at sqrt s written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper presents measurements from the ATLAS experiment of the forward-backward asymmetry in the reaction pp 2!Z/[gamma] * 2!l + l -, with l being electrons or muons, and the extraction of the effective weak mixing angle. The results are based on the full set of data collected in 2011 in pp collisions at the LHC at \(\sqrt{s}=7 \) TeV, corresponding to an integrated luminosity of 4.8 fb-1. The measured asymmetry values are found to be in agreement with the corresponding Standard Model predictions. The combination of the muon and electron channels yields a value of the effective weak mixing angle of sin2 [theta] eff lept =0.2308"0.0005(stat.)"0.0006(syst.)"0.0009(PDF), where the first uncertainty corresponds to data statistics, the second to systematic effects and the third to knowledge of the parton density functions. This result agrees with the current world average from the Particle Data Group fit.
Download or read book Measurement of the Forward backward Asymmetry of Electron and Muon Pair production in Pp 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: This study presents measurements from the ATLAS experiment of the forward-backward asymmetry in the reaction pp → Z/? * →l+l-, with l being electrons or muons, and the extraction of the effective weak mixing angle. The results are based on the full set of data collected in 2011 in pp collisions at the LHC at ( sqrt{s}=7 ) TeV, corresponding to an integrated luminosity of 4.8 fb-1. The measured asymmetry values are found to be in agreement with the corresponding Standard Model predictions. The combination of the muon and electron channels yields a value of the effective weak mixing angle of sin2 ?efflept =0.2308±0.0005(stat.)±0.0006(syst.)±0.0009(PDF), where the first uncertainty corresponds to data statistics, the second to systematic effects and the third to knowledge of the parton density functions. This result agrees with the current world average from the Particle Data Group fit.
Download or read book Measurement of the Forward backward Asymmetry of Electron and Muon Pair production in Pp Collisions at arrow written by and published by . This book was released on 2015 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper presents measurements from the ATLAS experiment of the forward-backward asymmetry in the reaction pp 2!Z/[gamma] * 2!l+l-, with l being electrons or muons, and the extraction of the effective weak mixing angle. The results are based on the full set of data collected in 2011 in pp collisions at the LHC at [arrow]"=7 TeV, corresponding to an integrated luminosity of 4.8 fb-1. The measured asymmetry values are found to be in agreement with the corresponding Standard Model predictions. The combination of the muon and electron channels yields a value of the effective weak mixing angle of sin2 [theta]efflept = 0.2308"0.0005(stat.)"0.0006(syst.)"0.0009(PDF), where the first uncertainty corresponds to data statistics, the second to systematic effects and the third to knowledge of the parton density functions. The result agrees with the current world average from the Particle Data Group fit.
Download or read book Measurement of the Forward Backward Asymmetry in Low Mass Bottom Quark Pairs Produced in Proton Antiproton Collisions written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We report a measurement of the forward-backward asymmetry, $A_{FB}$, in $b\bar{b}$ pairs produced in proton-antiproton collisions and identified by muons from semileptonic $b$-hadron decays. The event sample was collected at a center-of-mass energy of $\sqrt{s}=1.96$ TeV with the CDF II detector and corresponds to 6.9 fb$^{-1}$ of integrated luminosity. We obtain an integrated asymmetry of $A_{FB}(b\bar{b})=(1.2 \pm 0.7)$\% at the particle level for $b$-quark pairs with invariant mass, $m_{b\bar{b}}$, down to $40$ GeV/$c^2$ and measure the dependence of $A_{FB}(b\bar{b})$ on $m_{b\bar{b}}$. The results are compatible with expectations from the standard model.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Forward backward Asymmetry of Drell Yan Lepton Pairs in Pp Collisions at sqrt s written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A measurement of the forward-backward asymmetry $A_{\mathrm{FB}}$ of oppositely charged lepton pairs ($\mu\mu$ and $\mathrm{ ee } $) produced via $\mathrm{ Z }/\gamma^*$ boson exchange in pp collisions at $\sqrt{s} =$ 8 TeV is presented. The data sample corresponds to an integrated luminosity of 19.7 fb$^{-1}$ collected with the CMS detector at the LHC. The measurement of $A_{\mathrm{FB}}$ is performed for dilepton masses between 40 GeV and 2 TeV and for dilepton rapidity up to 5. The $A_{\mathrm{FB}}$ measurements as a function of dilepton mass and rapidity are compared with the standard model predictions.
Download or read book First Measurement of the Forward backward Asymmetry in Bottom quark Pair Production at High Mass written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We measure the particle-level forward-backward production asymmetry in $\mathrm{b\bar{b}}$ pairs with masses (m$\mathrm{b\bar{b}}$) larger than 150 GeV/c2, using events with hadronic jets and employing jet charge to distinguish b from $\bar{b}$. The measurement uses 9.5 fb-1 of $\mathrm{p\bar{p}}$ collisions at a center-of-mass energy of 1.96 TeV recorded by the CDF II detector. The asymmetry as a function of m$\mathrm{b\bar{b}}$ is consistent with zero, as well as with the predictions of the standard model. The measurement disfavors a simple model including an axigluon with a mass of 200 GeV/c2, whereas a model containing a heavier 345 GeV/c2 axigluon is not excluded.
Download or read book Measurement of the Forward backward Asymmetry of Z Boson Decays in Electron positron Pairs with the ATLAS Detector in Proton proton Collisions at Root Out S written by Sebastian König and published by . This book was released on 2014 with total page 133 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of the Forward backward Asymmetry of Z Boson Decays in Electron positron Pairs with the ATLAS Detector in Proton proton Collisions at Root Out s written by Sebastian König and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Forward Backward Asymmetry at High Mass in t bar t Production in p bar p Collisions at sqrt s written by and published by . This book was released on 2011 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt: Current understanding of particle physics postulates that there are 17 fundamental particles that interact via four fundamental forces - gravity, the strong force, the weak force, and the electromagnetic force. These fundamental particles can be classified by their spins into bosons, which are the force-carrying particles with integer spins, and fermions, which have half-integer spins. Fermions can be further divided into quarks and leptons. The particles and three of the four forces - all but gravity - are described by the Standard Model, a local SU(3) x SU(2) x U(1) gauge theory. Electromagnetic and weak interactions as described by Electroweak Theory or Quantum Electrodynamics, SU(2) x U(1). Strong interactions are described by Quantum Chromodynamics or QCD, SU(3). Fermions are grouped into three generations as shown in Table 1.1. Each generation consists of a leptonic doublet containing a charged and a neutral lepton and a weak isospin doublet containing two quarks. The first generation, containing the electron, the electron neutrino, the up quark, and the down quark, is the lightest generation and is thus the most frequently found in nature. The second generation contains the muon, the muon neutrino, the strange quark, and the charm quark. The third generation contains the tau, the tau neutrino, the bottom quark, and the top quark.
Download or read book A Measurement of Forward backward Charge Asymmetry of Electron positron Pairs in Proton antiproton Collision at 1 8 TeV written by Gregory Francisco Veramendi and published by . This book was released on 2003 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present a measurement of the mass dependence of the forward-backward charge asymmetry for e{sup +}e{sup -} pairs resulting from {gamma}*/Z decays with mass M{sub ee}> 40 GeV/c{sup 2}. The Run II data sample consists of 72 pb{sup -1} of data, which was collected by the CDF detector in {bar p}p collisions at {radical}s = 1.96 TeV at the Fermilab Tevatron. The measurement is compared with predictions from the Standard Model.
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 the t bar t Production Cross Section in Pp Collisions at sqrt s written by and published by . This book was released on 2014 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: The top-quark pair production cross section is measured in final states with one electron or muon and one hadronically decaying [tau] lepton from the process $t\bar{t}$ to (l[nu]l) ([tau][nu][tau]) $b\bar{b}$, where l = e, [mu]. The data sample corresponds to an integrated luminosity of 19.6 fb-1 collected with the CMS detector in proton-proton collisions at $\sqrt{s}$ =8 TeV. The measured cross section [sigma]$t\bar{t}$ = 257 ± 3 (stat) ± 24 (syst) ± 7 (lumi) pb, assuming a top-quark mass of 172.5 GeV, is consistent with the standard model prediction.
Download or read book Measurement of Prompt J psi Pair Production in Pp Collisions at sqrt s written by and published by . This book was released on 2014 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt: Production of prompt J/[psi] meson pairs in proton-proton collisions at √s = 7 TeV is measured with the CMS experiment at the LHC in a data sample corresponding to an integrated luminosity of about 4.7 fb-1. The two J/[psi] mesons are fully reconstructed via their decays into [mu] + [mu] - pairs. This observation provides for the first time access to the high-transverse-momentum region of J/[psi] pair production where model predictions are not yet established. The total and differential cross sections are measured in a phase space defined by the individual J/[psi] transverse momentum (p T J/[psi] ) and rapidity (
Download or read book Measurement of the Prompt J Psi Pair Production Cross Section in Pp Collisions at Sqrt s written by Grant Valentine Riley and published by . This book was released on 2017 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: The cross section for the prompt production of [J/Psi] meson pairs in proton-proton collisions at √ s[sqrt(s)] = 8 TeV at the LHC from a sample corresponding to an integrated luminosity of 20.2±0.5 fb−1 [inverse femtobarns] has been measured with the CMS detector. It provides unique insight into particle production and proton structure in proton-proton (pp) collisions. The two [J/Psi] mesons are fully reconstructed in their [mu+ mu-] decay. An acceptance region is defined by the individual [J/Psi] transverse momentum p [J/Psi pT] and rapidity y [J/Psi Rapidity]. The total fiducial cross section assuming unpolarized prompt [J/Psi] pair production is found to be [sigma_fid] = 195.7 ± 11.1 (stat) ± 22.1 (syst) ± 5.1 (lumi) ± 2.3 (BF) pb. The differential cross sections for prompt [J/Psi] pair production within this acceptance region are measured in eight event variables. Most predictions for particle production in pp collisions at the LHC assume dominance of single parton (gluon, quark) interactions (SPS) at the leading order perturbation theory. This assumption is tested with the final state measured in this analysis. Significant contributions from next-to-leading order processes and double parton scattering (DPS) are observed. In addition, the single [J/Psi] production cross section is estimated from theory and measured with pp collision data. Single [J/Psi] production is compared to the pair production via DPS and quantified via an effective cross section. This quantity is further compared to several particle pair production processes. In particular, the [J/Psi] pair production probes the contributions of gluons. All particle production measurements with CMS depend on the precise knowledge of the LHC luminosity. A detector, the Pixel Luminosity Telescope, based on solid state technology is used to count charged particle tracks from pp collisions, a measure of the instantaneous luminosity. The measurement is provided online for every crossing of the LHC beams. Tests of sensors and the development work for the detector are presented.
Download or read book MEASUREMENT OF SINGLE TRANSVERSE SPIN ASYMMETRY IN FORWARD PRODUCTION OF PHOTONS AND NEUTRONS IN PP COLLSION AT SQUARE ROOT written by and published by . This book was released on 2002 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Relativistic Heavy Ion Collider (RHIC) at the Brookhaven National Laboratory (BNL) was commissioned for polarized proton-proton collisions, at the center of mass energy (square root)s = 200 GeV during the run in 2001-2002. The authors have measured the single transverse-spin asymmetry A{sub N} for production of photons, neutral pions, and neutrons at the very forward angle. The asymmetries for the photon and neutral pion sample were consistent with zero within the experimental uncertainties. In contrast, the neutron sample exhibited an unexpectedly large asymmetry. This large asymmetry will be used for the non-destructive polarimeter for polarized proton beams at the collision points in the RHIC interaction region.
Download or read book Forward backward Asymmetry of Drell Yan Lepton Pairs in Pp Collisions at s written by CMS Collaboration and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
