Updated predictions for the total production cross sections of top and of heavier quark pairs at the Tevatron and at the LHC

Abstract

We present updated predictions for the total production cross section of topquark pairs at the Tevatron and at the LHC, and, at the LHC, of heavy-quark pairs with mass in the range 0.5 − 2 TeV. For tt production at the LHC we also present results at √ S = 10 TeV, in view of the expected accelerator conditions during the forthcoming 2008 run. Our results are accurate at the level of next-to-leading order in α S , and of next-toleading threshold logarithms (NLO+NLL). We adopt the most recent parametrizations of parton distribution functions, and compute the corresponding uncertainties. We study the dependence of the results on the top mass, and we assess the impact of missing higher-order corrections by independent variations of factorisation and renormalisation scales.

Higgs production at the lHC

“…This procedure has been in fact already proposed, together with other possibilities which give similar results, in ref. [91] where top quark pair production at hadron colliders was discussed. An argument for the approach put forward in ref.…”

Measurement of $ {\text{B}}\overline {\text{B}} $ angular correlations based on secondary vertex reconstruction at $ \sqrt {s} = 7\,{\text{TeV}} $

“…At higher orders in QCD, the FCR, FEX and GSP separation of production subprocesses becomes meaningless and only the combination of the 2 → 2 and 2 → 2 + n (n ≥ 1) subprocesses is relevant. Calculations of such processes are implemented in mc@nlo [12][13][14] or fonll [15]. The MadGraph/madevent [16,17] generator provides the possibility to simulate 2 → 2, 3 subprocesses at tree-level, providing a hybrid solution between 2 → 2 at LO and the NLO simulations.…”

Two-loop leading color corrections to heavy-quark pair production in the gluon fusion channel

“…In several cases, the next-to-leading (NLO) corrections have been supplemented by the resummation of large logarithmic corrections at leading (LL, [25][26][27][28][29][30][31]), next-to-leading (NLL, [32][33][34][35][36][37][38]) and next-to-next-to-leading logarithmic (NNLL, [39][40][41][42][43]) accuracy. However, to match the precision of the forthcoming experimental data, full next-to-next-to-leading order (NNLO) calculations are required for at least some of the observables, such as the top-quark pair production total cross section [44][45][46][47][48].…”