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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[pole over t], or the strong coupling constant, α[subscript S]. With the parton distribution function set NNPDF2.3, a pole mass of 176.7[+3.8 over −3.4] GeV is obtained when constraining α[subscript S] at the scale of the Z boson mass, m[subscript Z], to the current world average. Alternatively, by constraining m[pole over t] to the latest average from direct mass measurements, a value of α[subscript S](m[subscript Z])= 0.1151[+0.0033 over −0.0032] is extracted. This is the first determination of α[subscript S] using events from top-quark production.
CMS Collaboration; Gaultney, Vanessa; Hewamanage, Samantha; Linn, Stephan; Markowitz, Pete E.; Martinez, German; and Rodriguez, Jorge Luis, "Determination of the top-quark pole mass and strong coupling constant from the t t-bar production cross section in pp collisions at sqrt(s) = 7 TeV" (2013). Department of Physics. 48.