Tuesday, July 9, 2013

1307.1907 (CMS Collaboration)

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

CMS Collaboration
The inclusive cross section for top-quark pair production measured by the CMS experiment in proton-proton 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, mtpole, or the strong coupling constant, alphaS. With the parton distribution function set NNPDF2.3, a pole mass of 176.7+3.8-3.4 GeV is obtained when constraining alphaS at the scale of the Z boson mass, mZ, to the current world average. Alternatively, by constraining mtpole to the latest average from direct mass measurements, a value of alphaS(mZ) = 0.1151+0.0033-0.0032 is extracted. This is the first determination of alphaS using events from top-quark production.
View original: http://arxiv.org/abs/1307.1907

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