Third-Order Fiducial Predictions for Drell-Yan Production at the LHC.

The Drell-Yan process at hadron colliders is a fundamental benchmark for the study of strong interactions and the extraction of electroweak parameters. The outstanding precision of the LHC demands very accurate theoretical predictions with a full account of fiducial experimental cuts. In this Letter we present a state-of-the-art calculation of the fiducial cross section and of differential distributions for this process at third order in the strict fixed-order expansion in the strong coupling, as well as including the all-order resummation of logarithmic corrections. Together with these results, we present a detailed study of the subtraction technique used to carry out the calculation for different sets of experimental cuts, as well as of the sensitivity of the fiducial cross section to infrared physics. We find that residual theory uncertainties are reduced to the percent level and that the robustness of the predictions can be improved by a suitable adjustment of fiducial cuts.

Erratum to: MiNNLOPS: a new method to match NNLO QCD to parton showers.

[This corrects the article DOI: 10.1007/JHEP05(2020)143.].

Next-to-Next-to-Leading Order Event Generation for Top-Quark Pair Production.

The production of top-quark pairs in hadronic collisions is among the most important reactions in modern particle physics phenomenology and constitutes an instrumental avenue to study the properties of the heaviest quark observed in nature. The analysis of this process at the Large Hadron Collider relies heavily on Monte Carlo simulations of the final state events, whose accuracy is challenged by the outstanding precision of experimental measurements. In this Letter we present the first matched computation of top-quark pair production at next-to-next-to-leading order in QCD with all-order radiative corrections as implemented via parton-shower simulations. Besides its intrinsic relevance for LHC phenomenology, this work also establishes an important step towards the simulation of other hadronic processes with color charges in the final state.

Jet cross sections at the LHC and the quest for higher precision.

We perform a phenomenological study of Z plus jet, Higgs plus jet and di-jet production at the Large Hadron Collider. We investigate in particular the dependence of the leading jet cross section on the jet radius as a function of the jet transverse momentum. Theoretical predictions are obtained using perturbative QCD calculations at the next-to and next-to-next-to-leading order, using a range of renormalization and factorization scales. The fixed order predictions are compared to results obtained from matching next-to-leading order calculations to parton showers. A study of the scale dependence as a function of the jet radius is used to provide a better estimate of the scale uncertainty for small jet sizes. The non-perturbative corrections as a function of jet radius are estimated from different generators.

The transverse momentum spectrum of weak gauge bosons at N 3 LL + NNLO.

We present accurate QCD predictions for the transverse momentum ( p ⊥ ) spectrum of electroweak gauge bosons at the LHC for 13 TeV collisions, based on a consistent combination of a NNLO calculation at large p ⊥ and N 3 LL resummation in the small p ⊥ limit. The inclusion of higher order corrections leads to substantial changes in the shape of the differential distributions, and the residual perturbative uncertainties are reduced to the few percent level across the whole transverse momentum spectrum. We examine the ratio of p ⊥ distributions in charged- and neutral-current Drell-Yan production, and study different prescriptions for the estimate of perturbative uncertainties that rely on different degrees of correlation between these processes. We observe an excellent stability of the ratios with respect to the perturbative order, indicating a strong correlation between the corresponding QCD corrections.

Constraining Light-Quark Yukawa Couplings from Higgs Distributions.

We propose a novel strategy to constrain the bottom and charm Yukawa couplings by exploiting Large Hadron Collider (LHC) measurements of transverse momentum distributions in Higgs production. Our method does not rely on the reconstruction of exclusive final states or heavy-flavor tagging. Compared to other proposals, it leads to an enhanced sensitivity to the Yukawa couplings due to distortions of the differential Higgs spectra from emissions which either probe quark loops or are associated with quark-initiated production. We derive constraints using data from LHC run I, and we explore the prospects of our method at future LHC runs. Finally, we comment on the possibility of bounding the strange Yukawa coupling.

Higgs Transverse-Momentum Resummation in Direct Space.

We propose a new approach to the resummation of the transverse-momentum distribution of a high-mass color-singlet system in hadronic collisions. The resummation is performed in momentum space and is free of kinematic singularities at small transverse momentum. We derive a formula accurate at the next-to-next-to-leading-logarithmic level, and present the first matched predictions to next-to-next-to-leading order for Higgs-boson production in gluon fusion at the LHC. This method can be adapted to all observables featuring kinematic cancellations in the infrared region.