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تسجيل مستخدم جديدIso-spin asymmetry of quark distributions and implications for single top-quark production at the LHC
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We present an improved determination of the up- and down-quark distributions in the proton using recent data on charged lepton asymmetries from $W^pm$ gauge-boson production at the LHC and Tevatron. The analysis is performed in the framework of a global fit of parton distribution functions. The fit results are consistent with a non-zero iso-spin asymmetry of the sea, $x(bar d - bar u)$, at small values of Bjorken $xsim 10^{-4}$ indicating a delayed onset of the Regge asymptotics of a vanishing $(bar d - bar u)$-asymmetry at small-$x$. We compare with up- and down-quark distributions available in the literature and provide accurate predictions for the production of single top-quarks at the LHC, a process which can serve as a standard candle for the light quark flavor content of the proton.
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