Top-Antitop Pair Production Close to Threshold Synopsis of Recent NNLO Results

Abstract

Using non-relativistic effective theories, new next-to-next-to-leading order (NNLO) QCD corrections to the total tt production cross section at the Linear Collider have been calculated recently. In this article the NNLO calculations of several groups are compared and the remaining uncertainties are discussed. The theoretical prospects for an accurate determination of top quark mass parameters are discussed in detail. An outlook on possible future improvements is given.

Soft gluon resummation for associated t t ¯ H $$ \mathrm{t}\overline{\mathrm{t}}\mathrm{H} $$ production at the LHC

“…We note that in general Coulomb corrections can also be resummed [46][47][48][49][50]. A combined resummation of Coulomb and soft corrections is, however, beyond the scope of this paper.…”

Physics impact of a precise determination of the top quark mass at an e+e−linear collider

“…Taking these uncertainties into account, an accuracy in the m t determination of δm t 100 MeV as quoted in eq. (1.1) seems to be feasible (for a review, see [4] and references therein). This requires an experimental accuracy of α s (M Z ) of about 0.001, which can be obtained from LC measurements also at the tt threshold [5], possibly from event shape measurements at the LC [6], and from LC measurements at GigaZ, where an even higher accuracy seems to be achievable [9].…”

Electroweak production of top-quark pairs ine+e−annihilation at NNLO in QCD: The vector current contributions

“…[6] and [7]. Total cross sections are known to NNLO in the threshold expansions [8][9][10][11][12] and high-energy expansions [13][14][15][16][17]. Results for the forwardbackward asymmetry are also known in the small mass approximation [18][19][20].…”