Soft-gluon resummations and NNNLO expansions

I discuss the effectiveness of soft-gluon resummations in describing higher-order corrections. I present a comparison of recent resummation approaches and their relative successes in approximating complete NNLO corrections. I also discuss fixed-order expansions through NNNLO and present some recent applications to QCD hard-scattering processes, including top-antitop pair production, single-top production, and W production at large transverse momentum.Comment: 7 pages, 7 figures; presented at EPS-HEP 2013, Stockholm, Sweden, July 18-24, 201

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

NNLO soft and virtual corrections for electroweak, Higgs, and SUSY processes.

I present applications of a master formula for next-to-next-to-leading order soft and virtual QCD corrections to various electroweak, Higgs, and supersymmetric processes. They include Drell-Yan and charged Higgs production, single-top production in flavor-changing neutral-current processes, and squark and gluino production

Theoretical results for electroweak-boson and single-top production

I present results from recent high-order calculations for the production of electroweak bosons and top quarks. In particular, I discuss $W$ and $Z$ boson production at large transverse momentum, single-top production, and FCNC top production. Theoretical predictions which include higher-order soft-gluon corrections are presented for total cross sections and differential distributions at the LHC.Comment: 6 pages, 4 figures; presented at the XXIII International Workshop on Deep-Inelastic Scattering and Related Subjects, Dallas, Texas, 27 April - 1 May 2015; to appear in PoS(DIS2015

Next-to-next-to-leading-order collinear and soft gluon corrections for t-channel single top quark production

I present the resummation of collinear and soft gluon corrections to single top quark production in the t channel at next-to-next-to-leading logarithm (NNLL) accuracy using two-loop soft anomalous dimensions. The expansion of the resummed cross section yields approximate next-to-next-to-leading order (NNLO) cross sections. Numerical results for t-channel single top quark (or single antitop) production at the Tevatron and the LHC are presented, including the dependence of the cross sections on the top quark mass, and the uncertainties from scale variation and parton distributions. Combined results for all single top quark production channels are also given.Comment: 11 pages, 4 figure

N3^3LO approximate results for top-quark differential cross sections and forward-backward asymmetry

I present a calculation of approximate N$^3$LO corrections from NNLL soft-gluon resummation for differential distributions in top-antitop pair production in hadronic collisions. Soft-gluon corrections are the dominant contribution to top-quark production and closely approximate exact results through NNLO. I show aN$^3$LO results for the total $t{\bar t}$ cross section, the top-quark $p_T$ and rapidity distributions, and the top-quark forward-backward asymmetry. The higher-order corrections are significant and they reduce theoretical uncertainties.Comment: 6 pages, 5 figures; presented at the XXIII International Workshop on Deep-Inelastic Scattering and Related Subjects, Dallas, Texas, 27 April - 1 May 2015; to appear in PoS(DIS2015