The European Physical Journal C > 2017 > 77 > 7 > 1-45
Measurement of double-differential cross sections for top quark pair production in pp collisions at $$\sqrt{s} = 8$$ s = 8 $$\,\text {TeV}$$ TeV and impact on parton distribution functions
Source
Abstract
Normalized double-differential cross sections for top quark pair ( $$\mathrm{t}\overline{\mathrm{t}}$$ t t ¯ ) production are measured in pp collisions at a centre-of-mass energy of 8 $$\,\text {TeV}$$ TeV with the CMS experiment at the LHC. The analyzed data correspond to an integrated luminosity of 19.7 $$\,\text {fb}^{-1}$$ fb - 1 . The measurement is performed in the dilepton $$\mathrm {e}^{\pm }\mu ^{\mp }$$ e ± μ ∓ final state. The $$\mathrm{t}\overline{\mathrm{t}}$$ t t ¯ cross section is determined as a function of various pairs of observables characterizing the kinematics of the top quark and $$\mathrm{t}\overline{\mathrm{t}}$$ t t ¯ system. The data are compared to calculations using perturbative quantum chromodynamics at next-to-leading and approximate next-to-next-to-leading orders. They are also compared to predictions of Monte Carlo event generators that complement fixed-order computations with parton showers, hadronization, and multiple-parton interactions. Overall agreement is observed with the predictions, which is improved when the latest global sets of proton parton distribution functions are used. The inclusion of the measured $$\mathrm{t}\overline{\mathrm{t}}$$ t t ¯ cross sections in a fit of parametrized parton distribution functions is shown to have significant impact on the gluon distribution.
Identifiers
journal ISSN : | 1434-6044 |
journal e-ISSN : | 1434-6052 |
DOI | 10.1140/epjc/s10052-017-4984-5 |