Suppression of Quantum Corrections by Classical Backgrounds

We use heat-kernel techniques in order to compute the one-loop effective action in the cubic Galileon theory for a background that realizes the Vainshtein mechanism. We find that the UV divergences are suppressed relative to the predictions of standard perturbation theory at length scales below the Vainshtein radius.Comment: 10 pages, 1 figure, major revision, inclusion of higher-order terms, version to appear in PR

Single-top and top-antitop cross sections

I present high-order calculations, including soft-gluon corrections, for single-top and top-antitop production cross sections and differential distributions. For single-top production, results are presented for the three different channels in the Standard Model, for associated production with a charged Higgs, and for processes involving anomalous couplings. For top-antitop pair production, total cross sections and top-quark transverse-momentum and rapidity distributions are presented for various LHC energies.Comment: 7 pages, 6 figures; presented at QCD@Work 2018, Matera, Italy, June 25-28, 201