# Measurement of double-differential cross sections for top quark pair production in pp collisions at \sqrt{s} = 8\, ext {TeV} and impact on parton distribution functions

Measurement of double-differential cross sections for top quark pair production in pp collisions at \sqrt{s} = 8\, ext {TeV} and impact on parton distribution functions - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

The European Physical Journal C

, 77:459

First Online: 11 July 2017Received: 05 March 2017Accepted: 09 June 2017

Abstract

Normalized double-differential cross sections for top quark pair \\mathrm{t}\overline{\mathrm{t}}\ production are measured in pp collisions at a centre-of-mass energy of 8\\,\text {TeV}\ with the CMS experiment at the LHC. The analyzed data correspond to an integrated luminosity of 19.7\\,\text {fb}^{-1}\. The measurement is performed in the dilepton \\mathrm {e}^{\pm }\mu ^{\mp }\ final state. The \\mathrm{t}\overline{\mathrm{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}}\ 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}}\ cross sections in a fit of parametrized parton distribution functions is shown to have significant impact on the gluon distribution.

Autor: A. M. Sirunyan - A. Tumasyan - W. Adam - E. Asilar - T. Bergauer - J. Brandstetter - E. Brondolin - M. Dragicevic - J. E