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, αS. With the parton distribution function set NNPDF2.3, a pole mass of 176.7−3.4+3.8GeV is obtained when constraining αSat the scale of the Z boson mass, mZ, to the current world average. Alternatively, by constraining mtpoleto the latest average from direct mass measurements, a value of αS(mZ)=0.1151−0.0032+0.0033is extracted. This is the first determination of αSusing events from top-quark production.

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

Albergo, S.;Chiorboli, M.;Costa, S.;Giordano, F.;Potenza, R.;Tricomi, A.;Tuve, C.;
2014-01-01

Abstract

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, αS. With the parton distribution function set NNPDF2.3, a pole mass of 176.7−3.4+3.8GeV is obtained when constraining αSat the scale of the Z boson mass, mZ, to the current world average. Alternatively, by constraining mtpoleto the latest average from direct mass measurements, a value of αS(mZ)=0.1151−0.0032+0.0033is extracted. This is the first determination of αSusing events from top-quark production.
CMS; Constant; Coupling; Cross section; Mass; Pair; Physics; QCD; Quark; Strong; Top; Nuclear and High Energy Physics
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11769/323136
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