Download or read book Measurement of the Cross Section of High Transverse Momentum u2192 Bb u00AF Production in Proton u2013 proton Collisions at u221A s written by and published by . This book was released on 2014 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Letter reports the observation of a high transverse momentum Z → bb¯ signal in proton–proton collisions at √s = 8 TeV and the measurement of its production cross section. The data analysed were collected in 2012 with the ATLAS detector at the LHC and correspond to an integrated luminosity of 19.5 fb–1. The Z → bb¯ decay is reconstructed from a pair of b-tagged jets, clustered with the anti-kt jet algorithm with R=0.4, that have low angular separation and form a dijet with pT > 200 GeV. The signal yield is extracted from a fit to the dijet invariant mass distribution, with the dominant, multi-jet background mass shape estimated by employing a fully data-driven technique that reduces the dependence of the analysis on simulation. The fiducial cross section is determined to be ?fidZ →bb¯ = 2.02 ± 0.20 (stat.) ± 0.25 (syst.) ± 0.06 (lumi.) pb = 2.02 ± 0.33 pb, in agreement with next-to-leading-order theoretical predictions.
Download or read book Measurements of the B Production Cross Section in Proton Antiproton Collisions at u221A s written by and published by . This book was released on 2006 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present a measurement of the cross section of b hadron (Hb) production in p$ar{p}$ collisions at √s = 1.96 TeV using the CDF II detector at the Fermilab Tevatron. They use 83 pb-1 of data taken between october 2002 and May 2003 that was collected with a trigger sensitive to high momentum muons and displaced tracks. They use partially reconstructed decays in the following modes: Hb → ?- $ar{v}$?D0X, D0 → K-?+, and Hb → ?-$ar{v}$?D*+ X, D*+ → D0?+, D0 → K- ?+, and their charge conjugates. They correct for the backgrounds from c$ar{c}$ and b$ar{b}$ decays, for trigger and reconstruction efficiencies, and for detector acceptance. They report the total cross section above a minimum transverse momentum (pT) of 9 GeV/c for the rapidity range.
Download or read book Measurement of Exclusive u2192 L l u2013 Production in Proton u2013 proton Collisions at u221A s written by and published by . This book was released on 2015 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Letter reports a measurement of the exclusive ?? → l+l– (l = e, ?) cross-section in proton-proton collisions at a centre-of-mass energy of 7 TeV by the ATLAS experiment at the LHC, based on an integrated luminosity of 4.6 fb–1. For the electron or muon pairs satisfying exclusive selection criteria, a fit to the dilepton acoplanarity distribution is used to extract the fiducial cross-sections. The cross-section in the electron channel is determined to be ?excl.?? → e+e– = 0.428 ± 0.035 (stat.) ± 0.018 (syst.) pbfor a phase-space region with invariant mass of the electron pairs greater than 24GeV, in which both electrons have transverse momentum pT > 12 GeV and pseudorapidity.
Download or read book Measurement of Total and Differential W W u2013 Production Cross Sections in Proton proton Collisions at sqrt s written by and published by . This book was released on 2016 with total page 81 pages. Available in PDF, EPUB and Kindle. Book excerpt: The production of W boson pairs in proton-proton collisions at √s = 8 TeV is studied using data corresponding to 20.3 fb–1 of integrated luminosity collected by the ATLAS detector during 2012 at the CERN Large Hadron Collider. The W bosons are reconstructed using their leptonic decays into electrons or muons and neutrinos. Events with reconstructed jets are not included in the candidate event sample. A total of 6636 WW candidate events are observed. Measurements are performed in fiducial regions closely approximating the detector acceptance. The integrated measurement is corrected for all acceptance effects and for the W branching fractions to leptons in order to obtain the total WW production cross section, which is found to be 71.1 ± 1.1(stat)–5.0+ 5.7(syst) ± 1.4(lumi) pb. This agrees with the next-to-next-to-leading-order Standard Model prediction of 63.2–1.4+1.6(scale) ± 1.2(PDF) pb. Fiducial differential cross sections are measured as a function of each of six kinematic variables. In conclusion, the distribution of the transverse momentum of the leading lepton is used to set limits on anomalous triple-gauge-boson couplings.
Download or read book Measurement of Total and Differential W W Production Cross Sections in Proton proton Collisions at sqrt s written by and published by . This book was released on 2016 with total page 81 pages. Available in PDF, EPUB and Kindle. Book excerpt: The production of W boson pairs in proton-proton collisions at √s = 8 TeV is studied using data corresponding to 20.3 fb-1 of integrated luminosity collected by the ATLAS detector during 2012 at the CERN Large Hadron Collider. The W bosons are reconstructed using their leptonic decays into electrons or muons and neutrinos. Events with reconstructed jets are not included in the candidate event sample. A total of 6636 WW candidate events are observed. Measurements are performed in fiducial regions closely approximating the detector acceptance. The integrated measurement is corrected for all acceptance effects and for the W branching fractions to leptons in order to obtain the total WW production cross section, which is found to be 71.1 ± 1.1(stat)-5.0+ 5.7(syst) ± 1.4(lumi) pb. This agrees with the next-to-next-to-leading-order Standard Model prediction of 63.2-1.4+1.6(scale) ± 1.2(PDF) pb. Fiducial differential cross sections are measured as a function of each of six kinematic variables. In conclusion, the distribution of the transverse momentum of the leading lepton is used to set limits on anomalous triple-gauge-boson couplings.
Download or read book Measurement of the Z Boson Differential Cross Section in Transverse Momentum and Rapidity in Proton proton Collisions at 8 TeV written by and published by . This book was released on 2015 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a measurement of the Z boson differential cross section in rapidity and transverse momentum using a data sample of pp collision events at a centre-of-mass energy √s=8 TeV, corresponding to an integrated luminosity of 19.7 fb-1. The Z boson is identified via its decay to a pair of muons. The measurement provides a precision test of quantum chromodynamics over a large region of phase space. In addition, due to the small experimental uncertainties in the measurement the data has the potential to constrain the gluon parton distribution function in the kinematic regime important for Higgs boson production via gluon fusion. The results agree with the next-to-next-to-leading-order predictions computed with the fewz program. The results are also compared to the commonly used leading-order MadGraph and next-to-leading-order powheg generators.
Download or read book Measurement of the Upsilon 1S Production Cross Section in Proton Proton Collisions at Center of Mass Energy 7 TeV written by Maxwell Ian Scherzer and published by . This book was released on 2011 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: A measurement of the cross section for upsilon(1S) production in proton-proton collisions at center of mass energy 7 TeV is presented. The measurement uses the upsilon(1S) 2!mu + mu decay mode and covers up to a transverse momentum of 26 GeV in two bins of rapidity; upsilon(1S) upsilon(1S) -1, collected with the ATLAS detector at the Large Hadron Collider. Templates derived from data are used to model the continuum background. In order to eliminate theoretical uncertainties due to the unknown polarization, the measurement is restricted to the case where both muons have a transverse momentum of p mu T> 4 GeV and a pseudorapidit
Download or read book First Measurement of the Cross Section for Top Quark Pair Production in Proton Proton Collisions at sqrt s written by and published by . This book was released on 2011 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first measurement of the cross section for top-quark pair production in pp collisions at the LHC at center-of-mass energy sqrt(s)= 7 TeV has been performed using 3.1 {\pm} 0.3 inverse pb of data recorded by the CMS detector. This result utilizes the final state with two isolated, highly energetic charged leptons, large missing transverse energy, and two or more jets. Backgrounds from Drell-Yan and non-W/Z boson production are estimated from data. Eleven events are observed in the data with 2.1 {\pm} 1.0 events expected from background. The measured cross section is 194 {\pm} 72 (stat.) {\pm} 24 (syst.) {\pm} 21 (lumi.) pb, consistent with next-to-leading order predictions.
Download or read book Measurement of the W W Cross Section in Pp Collisions at sqrt s written by and published by . This book was released on 2015 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: A measurement of the W boson pair production cross section in proton-proton collisions at [arrow]"s = 8 TeV is presented. The data we collected with the CMS detector at the LHC correspond to an integrated luminosity of 19.4 fb-1 . The W+W- candidates are selected from events with two charged leptons, electrons or muons, and large missing transverse energy. The measured W+W- cross section is 60.1 " 0.9 (stat) " 3.2 (exp) " 3.1 (theo) " 1.6 (lumi) pb = 60.1 " 4.8 pb, consistent with the standard model prediction. The W+W-cross sections are also measured in two different fiducial phase space regions. The normalized differential cross section is measured as a function of kinematic variables of the final-state charged leptons and compared with several perturbative QCD predictions. Limits on anomalous gauge couplings associated with dimension-six operators are also given in the framework of an effective field theory. Finally, the corresponding 95% confidence level intervals are -5.7
Download or read book Measurement of the Top antitop Production Cross Section in Pp Collisions at Sqrt s written by and published by . This book was released on 2011 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: A measurement of the top-antitop production cross section in proton-proton collisions at a centre-of-mass energy of 7 TeV has been performed at the LHC with the CMS detector. The analysis uses a data sample corresponding to an integrated luminosity of 36 inverse picobarns and is based on the reconstruction of the final state with one isolated, high transverse-momentum electron or muon and three or more hadronic jets. The kinematic properties of the events are used to separate the top-antitop signal from W+jets and QCD multijet background events. The measured cross section is 173 + 39 - 32 (stat. + syst.) pb, consistent with standard model expectations.
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
Download or read book Measurement of the W W Cross Section in Pp Collisions at sqrt s written by and published by . This book was released on 2016 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt: A measurement of the W boson pair production cross section in proton-proton collisions at √ s = 8 TeV is presented. The data we collected with the CMS detector at the LHC correspond to an integrated luminosity of 19.4 fb-1 . The W+W- candidates are selected from events with two charged leptons, electrons or muons, and large missing transverse energy. The measured W+W- cross section is 60.1 ± 0.9 (stat) ± 3.2 (exp) ± 3.1 (theo) ± 1.6 (lumi) pb = 60.1 ± 4.8 pb, consistent with the standard model prediction. The W+W-cross sections are also measured in two different fiducial phase space regions. In addition, the normalized differential cross section is measured as a function of kinematic variables of the final-state charged leptons and compared with several perturbative QCD predictions. Limits on anomalous gauge couplings associated with dimension-six operators are also given in the framework of an effective field theory. Finally, the corresponding 95% confidence level intervals are -5.7 csubWWW/sub/?sup2/sup 5.9 TeVsup-2/sup, -11.4 csubW/sub/?sup2/sup 5.4 TeVsup-2/sup , -29.2 csubB
Download or read book Measurement of W W Production Cross Section in Proton proton Collisions at s written by Baishali Dutta and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of the Production Cross Section for a W Boson and Two B Jets 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:
Download or read book Measurement of the Transverse Momentum Spectra of Weak Vector Bosons Produced in Proton proton 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 transverse momentum spectra of weak vector bosons are measured in the CMS experiment at the LHC. The measurement uses a sample of proton-proton collisions at sqrt(s) = 8 TeV, collected during a special low-luminosity running that corresponds to an integrated luminosity of 18.4 inverse-picobarns. The production of W bosons is studied in both electron and muon decay modes, while the production of Z bosons is studied using only the dimuon decay channel. The ratios of W- to W+ and Z to W differential cross sections are also measured. The measured differential cross sections and ratios are compared with theoretical predictions up to next-to-next leading order in QCD.
Download or read book Measurement of the Double differential Inclusive Jet Cross Section in Proton proton Collisions at u221A s written by and published by . This book was released on 2016 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Here, a measurement of the double-differential inclusive jet cross section as a function of jet transverse momentum pT and absolute jet rapidity.
Download or read book Measurement of the B c pm Production Cross Section in p bar p 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: Here, we describe a measurement of the ratio of the cross sections times branching fractions of the Bc+ meson in the decay mode Bc+ → J/[psi][mu]+[nu] to the B+ meson in the decay mode B+ → J/[psi]K+ in proton-antiproton collisions at center-of-mass energy √s = 1.96 TeV. The measurement is based on the complete CDF Run II data set, which comes from an integrated luminosity of 8.7 fb-1. The ratio of the production cross sections times branching fractions for Bc+ and B+ mesons with momentum transverse to the beam greater than 6 GeV/c and rapidity magnitude smaller than 0.6 is 0.211 ± 0.012(stat)-0.020+0.021(syst). Using the known B+ → J/[psi]K+ branching fraction, the known B+ production cross section, and a selection of the predicted Bc+ → J/[psi][mu]+[nu] branching fractions, the range for the total Bc+ production cross section is estimated.
