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Book Measurement of the Inclusive  Z  to Ee  Production Cross Section in Proton Proton Collisions at   sqrt s

Download or read book Measurement of the Inclusive Z to Ee Production Cross Section in Proton Proton Collisions at sqrt s written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis comprises a precision measurement of the inclusive \Zee production cross section in proton-proton collisions provided by the Large Hadron Collider (LHC) at a center-of-mass energy of $\sqrt{s}=7$~TeV and the absolute luminosity based on \Zee decays. The data was collected by the Compact Muon Solenoid (CMS) detector near Geneva, Switzerland during the year of 2010 and corresponds to an integrated luminosity of $\int\mathcal{L}dt = 35.9\pm 1.4$~pb$^{-1}$. Electronic decays of $Z$ bosons allow one of the first electroweak measurements at the LHC, making the cross section measurement a benchmark of physics performance after the first year of CMS detector and LHC machine operations. It is the first systematic uncertainty limited \Zee cross section measurement performed at $\sqrt{s}=7$~TeV. The measured cross section pertaining to the invariant mass window $M_{ee}\in (60,120)$~GeV is reported as: $\sigma(pp\to Z+X) \times \mathcal{B}(Z\to ee) = 997 \pm 11 \mathrm{(sta t)} \pm 19 \mathrm{(syst)} \pm 40 \mathrm{(lumi)} \textrm{ pb}$, which agrees with the theoretical prediction calculated to NNLO in QCD. Leveraging \Zee decays as ``standard candles'' for measuring the absolute luminosity at the LHC is examined; they are produced copiously, are well understood, and have clean detector signatures. Thus the consistency of the inclusive \Zee production cross section measurement with the theoretical prediction motivates inverting the measurement to instead use the \Zee signal yield to measure the luminosity. The result, which agrees with the primary relative CMS luminosity measurement calibrated using Van der Meer separation scans, is not only the most precise absolute luminosity measurement performed to date at a hadron collider, but also the first one based on a physics signal at the LHC.

Book Measurement of the Inclusive W and Z Production Cross Sections in Pp Collisions at    sqrt  s

Download or read book Measurement of the Inclusive W and Z Production Cross Sections in Pp Collisions at sqrt s written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A measurement of inclusive W and Z production cross sections in pp collisions at sqrt(s)=7 TeV is presented. The electron and muon decay channels are analyzed in a data sample collected with the CMS detector at the LHC and corresponding to an integrated luminosity of 36 inverse picobarns. The measured inclusive cross sections are sigma(pp-> WX) B(W-> l nu) = 10.30 +/- 0.02 (stat.) +/- 0.10 (syst.) +/- 0.10 (th.) +/- 0.41 (lumi.) nb and sigma(pp -> ZX) B(Z-> l+̂l-̂) = 0.974 +/- 0.007 (stat.) +/- 0.007 (syst.) +/- 0.018 (th.) +/- 0.039 (lumi.) nb, limited to the dilepton invariant mass range 60 to 120 GeV. The luminosity-independent cross section ratios are [sigma(pp->WX) B(W-> l nu)]/[sigma(pp-> ZX) B(Z->l+̂l-̂)] = 10.54 +/- 0.07 (stat.) +/- 0.08 (syst.) +/- 0.16 (th.) and [sigma(pp->W+̂X) B(W+̂ -> l+̂nu)] / [sigma(pp->W-̂ X) B(W-̂ -> l-̂ nu)] = 1.421 +/- 0.006 (stat.) +/- 0.014 (syst.) +/- 0.029 (th.). The measured values agree with next-to-next-to-leading order QCD cross section calculations based on recent parton distribution functions.

Book Measurement of the Inclusive Upsilon Production Cross Section in Pp Collisions at Sqrt s

Download or read book Measurement of the Inclusive Upsilon Production Cross Section in Pp Collisions at Sqrt s written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Upsilon production cross section in proton-proton collisions at sqrt(s) = 7 TeV is measured using a data sample collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 3.1 +/- 0.3 inverse picobarns. Integrated over the rapidity range.

Book Measurement of the Z      tau   tau  Production Cross section in Proton proton Collisions at  square Root Of  S

Download or read book Measurement of the Z tau tau Production Cross section in Proton proton Collisions at square Root Of S written by Justin Griffiths and published by . This book was released on 2012 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first measurement of the inclusive cross-section of the Z boson decaying to two tau leptons was measured with the ATLAS detector at the LHC. The data sample in this analysis represents an integrated luminosity of 35 pb ̄1 of proton-proton collisions at a center of mass energy of sqrt(s)=7 TeV. Separate measurements were performed in four decay modes based on how the two tau leptons decay: to hadrons and an electron, to hadrons and a muon, to an electron and a muon, and to two muons. In all four final states, inclusive cross-section measurements were made both in the fiducial region of the ATLAS detector where acceptance is high and in the full phase space, restricted to the mass range of [66, 116] GeV. The measurements from the four individual channels were then combined to yield the combined Z --> [tau] [tau] cross-section of 970 ± 70 (stat.) ± 60 (sys.) ± 30 (lumi.) pb.

Book Measurement of W and Z Boson Production Cross Sections in Proton proton Collisions at  square Root  S

Download or read book Measurement of W and Z Boson Production Cross Sections in Proton proton Collisions at square Root S written by Stephanie Akemi Brandt and published by . This book was released on 2020 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of W and Z boson production cross sections in pp collisions at [square root] s = 5.02TeV and [square root] s = 13TeV are presented. Data was collected by the CMS experiment at the LHC during low-pileup data taking periods in 2017. The corresponding integrated luminosity for the data is 299.1 ± 5 pb−1 ( [square root] s = 5.02TeV) and 199.3 ± 4 pb−1 ( [square root] s = 13TeV), with an average number of pile-up interactions [[mu] = 3 ([mu] = 2). Cross sections and cross section ratios are reported, with final states in electron and muon channels.

Book Measurement of the Production Cross Sections for a Z Boson and One Or More B Jets in Pp Collisions at Sqrt s

Download or read book Measurement of the Production Cross Sections for a Z Boson and One Or More B Jets in Pp Collisions at Sqrt s written by and published by . This book was released on 2014 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: The production of a Z boson, decaying into two leptons and produced in association with one or more b jets, is studied using proton-proton collisions delivered by the LHC at a centre-of-mass energy of 7 TeV. The data were recorded in 2011 with the CMS detector and correspond to an integrated luminosity of 5 fb-1. The Z(ll) + b-jets cross sections (where ll = [mu][mu] or ee) are measured separately for a Z boson produced with exactly one b jet and with at least two b jets. In addition, a cross section ratio is extracted for a Z boson produced with at least one b jet, relative to a Z boson produced with at least one jet. The measured cross sections are compared to various theoretical predictions, and the data favour the predictions in the five-flavour scheme, where b quarks are assumed massless. The kinematic properties of the reconstructed particles are compared with the predictions from the MadGraph event generator using the pythia parton shower simulation.

Book Measurements of Inclusive W and Z Cross Sections in Pp Collisions at Sqrt s

Download or read book Measurements of Inclusive W and Z Cross Sections in Pp Collisions at Sqrt s written by and published by . This book was released on 2011 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of inclusive W and Z boson production cross sections in pp collisions at sqrt(s)=7 TeV are presented, based on 2.9 inverse picobarns of data recorded by the CMS detector at the LHC. The measurements, performed in the electron and muon decay channels, are combined to give sigma(pp to WX) times B(W to muon or electron + neutrino) = 9.95 \pm 0.07(stat.) \pm 0.28(syst.) \pm 1.09(lumi.) nb and sigma(pp to ZX) times B(Z to oppositely charged muon or electron pairs) = 0.931 \pm 0.026(stat.) \pm 0.023(syst.) \pm 0.102(lumi.) nb. Theoretical predictions, calculated at the next-to-next-to-leading order in QCD using recent parton distribution functions, are in agreement with the measured cross sections. Ratios of cross sections, which incur an experimental systematic uncertainty of less than 4%, are also reported.

Book Generator level Acceptance for the Measurement of the Inclusive Cross Section of W boson and Z boson Production in Pp Collisions at  square Root Of  S

Download or read book Generator level Acceptance for the Measurement of the Inclusive Cross Section of W boson and Z boson Production in Pp Collisions at square Root Of S written by Alexander Andriatis and published by . This book was released on 2018 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: The inclusive cross section of vector boson production in proton-proton collisions is one of the key measurements for constraining the Standard Model and an important part of the physics program at the LHC. Measurement of the inclusive cross section requires calculating the detector acceptance of decay products. The acceptance of the CMS detector of leptonic decays of W and Z bosons produced in pp colisions at [square root of]s = 5 TeV is calculated using Monte Carlo event simulation. Statistical and systematic uncertainties on the acceptance measurement from PDF and a, uncertainty and higher-order correction are reported. The use of the calculated acceptance in combination with measurements of detector efficiency, luminosity, and particle counting to determine the inclusive cross section is outlined. A total integrated luminosity of 331.64 pb-1 from 2015 and 2017 CMS data at [square root of]s = 5 TeV is available for the calculation of the inclusive cross section.

Book Measurement of the Inclusive Isolated Prompt Photon Cross Section in Pp Collisions at    sqrt s

Download or read book Measurement of the Inclusive Isolated Prompt Photon Cross Section in Pp Collisions at sqrt s written by and published by . This book was released on 2016 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: A measurement of the cross section for the inclusive production of isolated prompt photons in proton-proton collisions at a centre-of-mass energy of √s = 8 TeV is presented. The measurement covers the pseudorapidity ranges.

Book Measurement of the  WZ  Production Cross Section in  pp  Collisions at   sqrt s

Download or read book Measurement of the WZ Production Cross Section 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: The WZ production cross section in proton-proton collisions at sqrt(s) = 13 TeV is measured with the CMS experiment at the LHC using a data sample corresponding to an integrated luminosity of 2.3 inverse femtobarns. The measurement is performed in the leptonic decay modes WZ to l nu l' l', where l, l'= e, mu. The measured cross section for the range 60

Book Measurement of WZ and ZZ Production in Pp Collisions at   sqrt s

Download or read book Measurement of WZ and ZZ Production in Pp Collisions at sqrt s written by and published by . This book was released on 2014 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements are reported of the WZ and ZZ production cross sections in proton-proton collisions at $\sqrt{s}$ = 8 TeV in final states where one Z boson decays to b-tagged jets. The other gauge boson, either W or Z, is detected through its leptonic decay (either $W \to e\nu, \mu\nu$ or $Z \to e^+ e^-, \mu^+ \mu^-$, or $\nu\bar{\nu})$. The results are based on data corresponding to an integrated luminosity of 18.9 inverse-femtobarns collected with the CMS detector at the Large Hadron Collider. The measured cross sections, $\sigma(pp \to WZ)$ = 30.7 $\pm$ 9.3 (stat.) $\pm$ 7.1 (syst.) $\pm$ 4.1 (th.) $\pm$ 1.0 (lum.) pb and $\sigma(pp \to ZZ)$ = 6.5 $\pm$ 1.7 (stat.) $\pm$ 1.0 (syst.) $\pm$ 0.9 (th.) $\pm$ 0.2 (lum.) pb, are consistent with next-to-leading order quantum chromodynamics calculations.

Book Measurement of the  ZZ  Production Cross Section in  pp  Collisions at   sqrt s

Download or read book Measurement of the ZZ Production Cross Section 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: The ZZ production cross section in proton-proton collisions at 13 TeV center-of-mass energy is measured using 3.2 fb–1 of data recorded with the ATLAS detector at the Large Hadron Collider. The considered Z boson candidates decay to an electron or muon pair of mass 66–116 GeV. The cross section is measured in a fiducial phase space reflecting the detector acceptance. It is also extrapolated to a total phase space for Z bosons in the same mass range and of all decay modes, giving 16.7+2.2–2.0(stat)+0.9–0.7(syst)+1.0–0.7(lumi) pb. Lastly, the results agree with standard model predictions.

Book Measurement of the  ZZ  Production Cross Section and  Z  to  ell    ell    ell   prime     ell   prime     Branching Fraction in  pp  Collisions at   sqrt s

Download or read book Measurement of the ZZ Production Cross Section and Z to ell ell ell prime ell prime Branching Fraction 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: Four-lepton production in proton-proton collisions, pp to (Z/gamma*)(Z/gamma*) to l+l-l'+l'-, where $l, l' = e or mu, is studied at a center-of-mass energy of 13 TeV with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 2.6 inverse femtobarns. The ZZ production cross section, sigma(pp to ZZ) = 14.6 +1.9/-1.8 (stat) +0.5/-0.3 (syst) +/- 0.2 (theo) +/- 0.4 (lumi) pb, is measured for events with two opposite-sign, same-flavor lepton pairs produced in the mass region 60 m[l+l-], m[l'+l'-]