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

İngilizce (OpenAlex)

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, m t pole , or the strong coupling constant, α S . With the parton distribution function set NNPDF2.3, a pole mass of 176.7 − 3.4 + 3.8 GeV is obtained when constraining α 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 α S ( m Z ) = 0.1151 − 0.0032 + 0.0033 is extracted. This is the first determination of α S using events from top-quark production.