Enhanced Supersymmetric Corrections to Top-Quark Production at the Tevatron

摘要

We calculate the one-loop supersymmetric electroweak-like and QCD-likecorrections to the top-quark pair-production cross section at the Tevatron,including the important effects of non-degenerate top-squarks and left-righttop-squark mixing. The largest electroweak effects yield a negative shift inthe cross section and are enhanced right below the threshold for top-quarkdecay into top-squark and higgsino-like neutralino, and can be as large as$-35\%$. The largest QCD effects are positive and are enhanced for lighttop-squark masses, and can be as large as $20\%$. Such shifts greatly exceedthe present theoretical uncertainty in the Standard Model prediction, andtherefore may be experimentally observable. We also explore the one-loop shiftsin scenarios containing light top-squarks and higgsino-like neutralinos thathave been recently proposed to explain various apparent experimental anomalies.