Download or read book Inclusive and Differential Measurements of the T T bar Charge Asymmetry in Proton proton Collisions at Sqrt s written by and published by . This book was released on 2012 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: The t t-bar charge asymmetry is measured in events containing a charged lepton (electron or muon) and at least four jets, one of which is identified as originating from b-quark hadronization. The analyzed dataset corresponds to an integrated luminosity of 5.0 inverse femtobarns collected with the CMS detector at the LHC. An inclusive and three differential measurements of the t t-bar charge asymmetry as a function of rapidity, transverse momentum, and invariant mass of the t t-bar system are presented. The measured inclusive t t-bar charge asymmetry is A(C) = 0.004 +/- 0.010 (stat.) +/- 0.011 (syst.). This result and the three differential measurements are consistent with zero asymmetry as well as with the predictions of the standard model.
Download or read book Inclusive and Differential Measurements of the mathrm T bar t Charge Asymmetry in Pp Collisions at sqrt s written by and published by . This book was released on 2015 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: The tt charge asymmetry is measured in proton-proton collisions at a centre-of-mass energy of 8 TeV. The data, collected with the CMS experiment at the LHC, correspond to an integrated luminosity of 19.7 fb-1 . Selected events contain an electron or a muon and four or more jets, where at least one jet is identified as originating from b-quark hadronization. The inclusive charge asymmetry is found to be 0.0010 " 0.0068 (stat) " 0.0037 (syst). In addition, differential charge asymmetries as a function of rapidity, transverse momentum, and invariant mass of the tt system are studied. For the first time at the LHC, our measurements are also performed in a reduced fiducial phase space of top quark pair production, with an integrated result of -0.0035 " 0.0072 (stat) " 0.0031 (syst). Additionally, all measurements are consistent within two standard deviations with zero asymmetry as well as with the predictions of the standard model.
Download or read book Measurements of the t bar t Charge Asymmetry Using the Dilepton Decay Channel 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: The t t-bar charge asymmetry in proton-proton collisions at $\sqrt{s} =$ 7 TeV is measured using the dilepton decay channel (ee, e mu, or mu mu). The data correspond to a total integrated luminosity of 5.0 inverse femtobarns, collected by the CMS experiment at the LHC. The t t-bar and lepton charge asymmetries, defined as the differences in absolute values of the rapidities between the reconstructed top quarks and antiquarks and of the pseudorapidities between the positive and negative leptons, respectively, are measured to be Ac = -0.010 +/- 0.017 (stat.) +/- 0.008 (syst.) and Aclep = 0.009 +/- 0.010 (stat.) +/- 0.006 (syst). The lepton charge asymmetry is also measured as a function of the invariant mass, rapidity, and transverse momentum of the t t-bar system. All measurements are consistent with the expectations of the standard model.
Download or read book Measurements of t bar T Charge Asymmetry Using Dilepton Final States in Pp Collisions at sqrt S written by and published by . This book was released on 2016 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: The charge asymmetry in $t \bar t$ events is measured using dilepton final states produced in pp collisions at the LHC at √s = 8 TeV. The data sample, collected with the CMS detector, corresponds to an integrated luminosity of 19.5 fb-1. The measurements are performed using events with two oppositely charged leptons (electrons or muons) and two or more jets, where at least one of the jets is identified as originating from a bottom quark. The charge asymmetry is measured from differences in kinematic distributions, unfolded to the parton level, of positively and negatively charged top quarks and leptons. The $t \bar t$ and leptonic charge asymmetries are found to be 0.011 ± 0.011 (stat) ± 0.007 (syst) and 0.003 ± 0.006 (stat) ± 0.003 (syst), respectively. Lastly, These results, as well as charge asymmetry measurements made as a function of $t \bar t$ system kinematic properties, are in agreement with predictions of the standard model.
Download or read book Longitudinal Double spin Asymmetry and Cross Section for Inclusivejet Production in Polarized Proton Collisions at Sqrt s written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We report a measurement of the longitudinal double-spinasymmetry A_LL and the differential cross section for inclusivemidrapidity jet production in polarized proton collisions at sqrt(s)=200GeV. The cross section data cover transverse momenta 5
Download or read book Measurement of the Differential Cross Section and Charge Asymmetry for Inclusive mathrm p mathrm p rightarrow mathrm W pm X Production at sqrt s written by and published by . This book was released on 2016 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: The differential cross section and charge asymmetry for inclusive pp → W± + X → [mu]±[nu] + X production at √s = 8 TeV are measured as a function of muon pseudorapidity. The data sample corresponds to an integrated luminosity of 18.8 inverse femtobarns recorded with the CMS detector at the LHC. Furthermore, these results provide important constraints on the parton distribution functions of the proton in the range of the Bjorken scaling variable x from 10E-3 to 10E-1.
Download or read book Measurement of the Differential Cross Sections of Inclusive Prompt And Non Prompt J psi Production in Proton Proton Collisions at sqrt s written by and published by . This book was released on 2013 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of the W Boson Charge Asymmetry in Proton proton Collisions at Sqrts written by Tai-Hua Lin and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of the Inclusive Energy Spectrum in the Very Forward Direction in Proton proton 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 differential cross section for inclusive particle production as a function of energy in proton-proton collisions at a center-of-mass energy of 13 TeV is measured in the very forward region of the CMS detector. The measurement is based on data collected with the CMS apparatus at the LHC, and corresponds to an integrated luminosity of 0.35 inverse microbarns. The energy is measured in the CASTOR calorimeter, which covers the pseudorapidity region -6.6
Download or read book Search for New Phenomena in Ttbar Events with Large Missing Transverse Momentum in Proton Proton Collisions at Sqrt s written by and published by . This book was released on 2013 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Longitudinal Double Spin Asymmetry for Inclusive Jet Production in Polarized Proton proton Collisions at square Root Of S written by Julie Marie Millane and published by . This book was released on 2008 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present the Inclusive Jet Longitudinal Double-Spin Asymmetry for polarized protons at \s = 200 GeV. The data were taken on the STAR experiment at RHIC during the 2005 run period and cover a jet transverse momentum range of 5
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:
Download or read book Measurement of the Differential and Double differential Drell Yan Cross Sections in Proton proton Collisions at Sqrt s written by and published by . This book was released on 2013 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of the differential and double-differential Drell-Yan cross sections are presented using an integrated luminosity of 4.5(4.8) inverse femtobarns in the dimuon (dielectron) channel of proton-proton collision data recorded with the CMS detector at the LHC at sqrt{s} = 7 TeV. The measured inclusive cross section in the Z-peak region (60-120 GeV) is \sigma(\ell \ell) = 986.4 +/- 0.6 (stat.) +/- 5.9 (exp. syst.) +/- 21.7 (th. syst.) +/- 21.7 (lum.) pb for the combination of the dimuon and dielectron channels. Differential cross sections $d\sigma/dm$ for the dimuon, dielectron, and combined channels are measured in the mass range 15 to 1500 GeV and corrected to the full phase space. Results are also presented for the measurement of the double-differential cross section d2̂\sigma/dm d.
Download or read book Measurement of the Double differential Inclusive Jet Cross Section in Proton proton 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:
Download or read book Measurement of the Longitudinal Double Spin Asymmetry for Dijet Production in Polarized Proton Proton Collisions at Sqrt s written by Daniel L. Olvitt and published by . This book was released on 2017 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding what contributes to the intrinsic angular momentum (spin) of the proton has been a major goal of the nuclear physics community. In the 1980s, it was discovered that quarks contribute 30% to the spin of the proton. This information led to a search to find other contributions to the spin of the proton. At STAR, the double spin asymmetry (ALL) is measured as it is sensitive to the polarized gluon distribution (Dg(x)). The STAR 2009 inclusive jet ALL at sqrt(s) = 200 GeV has been incorporated into two independent global fits. These fits show for the first time a statistically significant non-zero gluon contribution to the spin of the proton in the parton momentum fraction range x > 0.05. Dijet ALL is also measured at STAR. Dijets are advantageous since the parton momentum fraction (x) of the initial partons may be reconstructed to first order from final state measurements. In 2013 STAR collected an estimated 250 pb-1 of data at sqrt(s) = 510 GeV. The higher center of mass energy will allow STAR to probe Dg(x) at x values as low as 0.02. The large statistics will allow a reduction in the uncertainties. Once the data is incorporated into future global fits, it will allow for a more precise determination of Dg(x). The 2013 dijet ALL results will be presented. The results show good agreement with both global fits and previous STAR results dijet measurements.
Download or read book Measurements of the Charge Asymmetry in Top quark Pair Production in the Dilepton Final State 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: Measurements of the top-antitop quark pair production charge asymmetry in the dilepton channel, characterized by two high-pT leptons (electrons or muons), are presented using data corresponding to an integrated luminosity of 20.3 fb–1 from pp collisions at a center-of-mass energy √s = 8 TeV collected with the ATLAS detector at the Large Hadron Collider at CERN. Inclusive and differential measurements as a function of the invariant mass, transverse momentum, and longitudinal boost of the tt¯ system are performed both in the full phase space and in a fiducial phase space closely matching the detector acceptance. Two observables are studied: AllC based on the selected leptons and Att¯C based on the reconstructed tt¯ final state. As a result, the inclusive asymmetries are measured in the full phase space to be AllC=0.008±0.006 and Att¯C=0.021±0.016, which are in agreement with the Standard Model predictions of AllC=0.0064±0.0003 and Att¯C=0.0111±0.0004.
Download or read book Top Physics written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a measurement of the t{bar t} production cross section using 194 pb−1 of CDF II data using events with a high transverse momentum electron or muon, three or more jets, and missing transverse energy. The measurement assumes 100% t --> Wb branching fraction. Events consistent with t{bar t} decay are found by identifying jets containing heavy flavor semileptonic decays to muons. The dominant backgrounds are evaluated directly from the data. Based on 20 candidate events and an expected background of 9.5 " 1.1 events, we measure a production cross section of 5.3 " 3.3{sub -1.0}{sup +1.3} pb, in agreement with the standard model.
