Download or read book Erratum to written by and published by . This book was released on 2015 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt: Table 4 was incorrectly captioned in the originally published version. The correct caption is 'Normalised differential tt- production cross section as a function of the number of additional jets with pT> 30 GeV in the lepton+jets channel. Furthermore, the statistical, systematic, and total uncertainties are also shown. Finally, the main experimental and model systematic uncertainties are displayed: JES and the combination of renormalisation and factorisation scales, jet-parton matching threshold, and hadronisation (in the table "Q2/Match./Had.")'.
Download or read book Measurement of mathrm T bar t Production with Additional Jet Activity Including B Quark Jets in the Dilepton Decay Channel Using Pp Collisions at sqrt s written by and published by . This book was released on 2015 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of the Ttbar Production Cross Section in the All jets Final State in Pp Collisions at sqrt s written by and published by . This book was released on 2015 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: The cross section for tt production in the all-jets final state is measured in pp collisions at a centre-of-mass energy of 8 TeV at the LHC with the CMS detector, in data corresponding to an integrated luminosity of 18.4 fb-1. The inclusive cross section is found to be 275.6 ±6.1 (stat) ± 37.8 (syst) ± 7.2 (lumi) pb. The normalized differential cross sections are measured as a function of the top quark transverse momenta, pT, and compared to predictions from quantum chromodynamics. The results are reported at detector, parton, and particle levels. In all cases, the measured top quark pT spectra are significantly softer than theoretical predictions.
Download or read book Measurement of the Jet Mass in Highly Boosted T tbar Events from Pp Collisions at sqrt s written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The first measurement of the jet mass m[jet] of top quark jets produced in t t-bar events from pp collisions at sqrt(s) = 8 TeV is reported for the jet with the largest transverse momentum pt in highly boosted hadronic top quark decays. The data sample, collected with the CMS detector, corresponds to an integrated luminosity of 19.7 inverse femtobarns. The measurement is performed in the lepton+jets channel in which the products of the semileptonic decay t to bW with W to l nu where l is an electron or muon, are used to select t t-bar events with large Lorentz boosts. The products of the fully hadronic decay t to bW with W to q q'-bar are reconstructed using a single Cambridge-Aachen jet with distance parameter R=1.2, and pt>400 GeV. The t t-bar cross section as a function of m[jet] is unfolded at the particle level and is used to test the modelling of highly boosted top quark production. The peak position of the m[jet] distribution is sensitive to the top quark mass m[t], and the data are used to extract a value of m[t] to assess this sensitivity.
Download or read book Inclusive B jet Production in Pp Collisions at Sqrt s written by and published by . This book was released on 2012 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: The inclusive b-jet production cross section in pp collisions at a center-of-mass energy of 7 TeV is measured using data collected by the CMS experiment at the LHC. The cross section is presented as a function of the jet transverse momentum in the range 18
Download or read book Measurement of the C jet Mistagging Efficiency in Tt over bar Events Using Pp Collision Data at square Root s written by [Study Group] ATLAS Collaboration CERN and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: A technique is presented to measure the efficiency with which c-jets are mistagged as b-jets (mistagging efficiency) using tt ̄ events, where one of the W bosons decays into an electron or muon and a neutrino and the other decays into a quark-antiquark pair. The measurement utilises the relatively large and known W→cs branching ratio, which allows a measurement to be made in an inclusive c-jet sample. The data sample used was collected by the ATLAS detector at s√=13 TeV and corresponds to an integrated luminosity of 139 fb−1. Events are reconstructed using a kinematic likelihood technique which selects the mapping between jets and tt ̄ decay products that yields the highest likelihood value. The distribution of the b-tagging discriminant for jets from the hadronic W decays in data is compared with that in simulation to extract the mistagging efficiency as a function of jet transverse momentum. The total uncertainties are in the range 3-17%. The measurements generally agree with those in simulation but there are some differences in the region corresponding to the most stringent b-jet tagging requirement
Download or read book Fragmentation Properties of Jets Produced in Pp Collisions at square Root Sign S written by Bradley Hubbard and published by . This book was released on 1989 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of the Charged particle Multiplicity Inside Jets from sqrt s written by and published by . This book was released on 2016 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: The number of charged particles inside jets is a widely used discriminant for identifying the quark or gluon nature of the initiating parton and is sensitive to both the perturbative and non-perturbative components of fragmentation. This paper presents a measurement of the average number of charged particles with pT > 500 MeV inside high-momentum jets in dijet events using 20.3 fb-1 of data recorded with the ATLAS detector in pp collisions at √s=8 TeV collisions at the LHC. The jets considered have transverse momenta from 50 GeV up to and beyond 1.5 TeV . The reconstructed charged-particle track multiplicity distribution is unfolded to remove distortions from detector effects and the resulting charged-particle multiplicity is compared to several models. Lastly, quark and gluon jet fractions are used to extract the average charged-particle multiplicity for quark and gluon jets separately.
Download or read book Measurements of Inclusive W jets Production Rates as a Function of Jet Transverse Momentum in p bar p Collisions at sqrt s written by and published by . This book was released on 2011 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Letter describes measurements of inclusive W(→ e[nu]) + n jet cross sections (n = 1-4), presented as total inclusive cross sections and differentially in the n{sup th} jet transverse momentum. The measurements are made using data corresponding to an integrated luminosity of 4.2 fb−1 collected by the D0 detector at the Fermilab Tevatron Collider, and achieve considerably smaller uncertainties on W+jets production cross sections than previous measurements. The measurements are compared to next-to-leading order perturbative QCD (pQCD) calculations in the n = 1-3 jet multiplicity bins and to leading order pQCD calculations in the 4-jet bin. The measurements are generally in agreement with pQCD predictions, although certain regions of phase space are identified where the calculations could be improved.
Download or read book Jet and Underlying Event Properties as a Function of Charged particle Multiplicity in Proton proton Collisions at Sqrt s written by and published by . This book was released on 2013 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt: Characteristics of multi-particle production in proton-proton collisions at sqrt(s) = 7 TeV are studied as a function of the charged-particle multiplicity, N[ch]. The produced particles are separated into two classes: those belonging to jets and those belonging to the underlying event. Charged particles are measured with pseudorapidity abs(eta) 2.4 and transverse momentum pt 0.25 GeV. Jets are reconstructed from charged-particles only and required to have pt> 5 GeV. The distributions of jet pt, average pt of charged particles belonging to the underlying event or to jets, jet rates, and jet shapes are presented as functions of N[ch] and compared to the predictions of the PYTHIA and HERWIG event generators. Predictions without multi-parton interactions fail completely to describe the N[ch]-dependence observed in the data. For increasing N[ch], PYTHIA systematically predicts higher jet rates and harder pt spectra than seen in the data, whereas HERWIG shows the opposite trends. At the highest multiplicity, the data-model agreement is worse for most observables, indicating the need for further tuning and/or new model ingredients.
Download or read book Measurement of Jets Produced in Top Quark Events Using the Emu Final State with 2 B tagged Jets in Pp Collisions at 8 TeV with the ATLAS Detector written by Jacquelyn Kay Brosamer and published by . This book was released on 2016 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: The transverse momentum and multiplicity of jets produced in top quark events are measured using 20.3 inverse fb of pp collision data at a center-of-mass energy of 8 tev. Jets are selected from top events requiring an opposite-charge $e\mu$ pair and two b-tagged jets in the final state. The data are corrected to obtain the particle-level fiducial cross section for additional jets with rank 1-4, where rank=1 is the leading additional jet. These distributions are used to obtain the extra jet multiplicity as a function of minimum jet pt threshold. The results are compared with several next to leading order Monte Carlo generators. The resulting measurements can be used to tune Monte Carlo QCD modelling and may also reduce associated modelling uncertainties for LHC top quark physics measurements.
Download or read book Jet Production Rates in Association with W and Z Bosons in Pp Collisions at sqrt s written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of jet production rates in association with W and Z bosons for jet transverse momenta above 30 GeV are reported, using a sample of proton-proton collision events recorded by CMS at sqrt(s) = 7 TeV, corresponding to an integrated luminosity of 36 inverse picobarns. The study includes the measurement of the normalized inclusive rates of jets sigma(V +>= n jets)/sigma(V), where V represents either a W or a Z. In addition, the ratio of W to Z cross sections and the W charge asymmetry as a function of the number of associated jets are measured. A test of Berends--Giele scaling at sqrt(s) = 7 TeV is also presented. The measurements provide a stringent test of perturbative-QCD calculations and are sensitive to the possible presence of new physics. The results are in agreement with the predictions of a simulation that uses explicit matrix element calculations for final states with jets.
Download or read book Shape Transverse Size and Charged Hadron Multiplicity of Jets in Pp Collisions at 7 TeV written by and published by . This book was released on 2012 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of jet characteristics from inclusive jet production in proton-proton collisions at a centre-of-mass energy of 7 TeV are presented. The data sample was collected with the CMS detector at the LHC during 2010 and corresponds to an integrated luminosity of 36 inverse picobarns. The mean charged hadron multiplicity, the differential and integral jet shape distributions, and two independent moments of the shape distributions are measured as functions of the jet transverse momentum for jets reconstructed with the anti-kT algorithm. The measured observables are corrected to the particle level and compared with predictions from various QCD Monte Carlo generators.
Download or read book Measurement of Jet Activity in Top Quark Events Using the E mu Final State with Two B tagged Jets in Pp Collisions at sqrt s written by and published by . This book was released on 2016 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Measurement of D Production in Jets from P P Collisions at square Root Of S written by George Redlinger and published by . This book was released on 1989 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modification of Jet Shapes in PbPb Collisions at sqrt s NN 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 first measurement of jet shapes, defined as the fractional transverse momentum radial distribution, for inclusive jets produced in heavy-ion collisions is presented. Data samples of PbPb and pp collisions, corresponding to integrated luminosities of 150 inverse microbarns and 5.3 inverse picobarns respectively, were collected at a nucleon-nucleon centre-of-mass energy of sqrt(s[NN]) = 2.76 TeV with the CMS detector at the LHC. The jets are reconstructed with the anti-kt algorithm with a distance parameter R=0.3, and the jet shapes are measured for charged particles with transverse momentum pt> 1 GeV. The jet shapes measured in PbPb collisions in different collision centralities are compared to reference distributions based on the pp data. A centrality-dependent modification of the jet shapes is observed in the more central PbPb collisions, indicating a redistribution of the energy inside the jet cone. This measurement provides information about the parton shower mechanism in the hot and dense medium produced in heavy-ion collisions.
Download or read book A Measurement of the Production Cross Section of Tt Pairs in Proton antiproton Collisions at square Root s written by Henri Bachacou and published by . This book was released on 2004 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt:
