Determination of the top-quark pole mass and strong coupling constant from the t(t)over-bar production cross section in pp collisions at root s=7 TeV


Chatrchyan S., Khachatryan V., Sirunyan A. M. , Tumasyan A., Adam W., Bergauer T., ...More

PHYSICS LETTERS B, vol.728, pp.496-517, 2014 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 728
  • Publication Date: 2014
  • Doi Number: 10.1016/j.physletb.2013.12.009
  • Title of Journal : PHYSICS LETTERS B
  • Page Numbers: pp.496-517
  • Keywords: CMS, Physics, Top, Quark, Pair, Cross section, Mass, QCD, Strong, Coupling, Constant, PARTON DISTRIBUTIONS, (MS)OVER-BAR MASSES, JETS

Abstract

The inclusive cross section for top-quark pair production measured by the CMS experiment in protonproton collisions at a center-of-mass energy of 7 TeV is compared to the QCD prediction at next-to-next-to-leading order with various parton distribution functions to determine the top-quark pole mass, m(t)(pole), or the strong coupling constant, alpha(S). With the parton distribution function set NNPDF2.3, a pole mass of 176.7(-3.4)(+3.8) GeV is obtained when constraining alpha(S) at the scale of the Z boson mass, m(Z), to the current world average. Alternatively, by constraining m(t)(pole) to the latest average from direct mass measurements, a value of alpha(S)(m(Z)) = 0.1151(-0.0032)(+0.0033) is extracted. This is the first determination of alpha(S) using events from top-quark production. (C) 2013 The Authors. Published by Elsevier B.V. All rights reserved.