arXiv subjects

Aude Gehrmann-De Ridder

Publications and source records attributed to Aude Gehrmann-De Ridder.

At least 19 recordsLinked to original sources

arXiv2026

Antenna subtraction at NNLO for heavy quark pair production at hadron colliders: the non-diagonal channels

We present the calculation involving the $qq$, $qq'$ and $qg$ partonic channels contributing to heavy-quark pair production at hadron colliders through next-to-next-to-leading order in QCD using the antenna subtraction formalism. The calculation is performed in full colour and implemented within the NNLOJET framework. Building upon previously available results, we complete the NNLO treatment of the $qq$ and $qq'$ channels by deriving the integrated subtraction contributions required at the real virtual and double-virtual levels. We further present for the first time the NNLO antenna subtraction terms related to the $qg$-channel in full colour. The calculation requires several new ingredients, including massive soft factors and convolutions involving integrated massive antennae thereby extending the integrated antenna library to cope with processes with massive fermions. We validate the calculation through analytic infrared pole cancellation and numerical comparisons with existing results. These results complete the NNLO description of the $qq$, $qq'$, and $qg$ channels and constitute an important step towards a fully differential NNLO treatment of heavy-quark pair production within the antenna subtraction formalism.

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arXiv2026

Boosted Higgs-strahlung off a $W$ boson at next-to-next-to-next-to-leading order in QCD

The production of a boosted Higgs boson in association with a charged weak ($W$) boson is a key process to scrutinize the electroweak symmetry breaking mechanism at hadron colliders. This reaction constitutes the dominant Higgs production channel at large transverse momentum, providing unique sensitivity to Higgs-boson interactions with other Standard Model particles as well as to physics beyond the Standard Model. In this Letter, we present the first fully differential calculation of this important scattering process at next-to-next-to-next-to-leading order (N$^3$LO) in perturbative Quantum Chromodynamics (QCD). We find that the N$^3$LO corrections, amounting to approximately $+2\%$ in the boosted regime, generally lie at the edge of or outside the standard scale variation band of the previous perturbative order. The residual dependence of the N$^3$LO prediction on perturbative scales is reduced to below the percent level, marking a milestone for the Higgs precision program.

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arXiv2026

Precise QCD Predictions for Hadron-in-jet Production in $e^+e^-$ Collisions

The production of identified hadrons inside jets in $e^+ e^-$ annihilation allows for detailed studies of parton-to-hadron fragmentation functions in a clean environment. We compute hadron-in-jets production cross sections for $e^+e^- \to 2\,\mathrm{jets}$ and $e^+e^- \to 3\,\mathrm{jets}$ to next-to-next-to-leading order (NNLO) in perturbative QCD. By comparing with data from the ALEPH experiment, we demonstrate the implications of the newly computed theory predictions for precision phenomenology.

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arXiv2025

NNLO+NNLL Predictions for Heavy-Jet Mass and C-parameter in Higgs Decays to Quarks and Gluons

We consider the resummation of large logarithmic corrections arising in the two-particle limit at next-to-next-to-leading logarithmic (NNLL) accuracy for the heavy-jet mass and $C$-parameter distributions in the decay of a Higgs boson to quarks and gluons: $H\to b\bar{b}$, $H\to c\bar{c}$, and $H\to gg$. We demonstrate how the matched NNLO+NNLL results clarify the relative contributions of key hadronic Higgs-decay channels ($H\to b\bar{b}$, $H\to c\bar{c}$, $H\to gg$) yielding reduced uncertainties for both event-shape observables -- especially for heavy-jet mass -- while revealing substantial effects that shift the $C$-parameter peak in gluonic decays.

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arXiv2025

NNLO QCD predictions for jet observables in ZH production at electron-positron colliders

We present precise predictions for a variety of jet observables in $ZH$ production at electron-positron colliders, with the $Z$ boson decaying leptonically and the Higgs boson decaying into two hadronic jets, up to NNLO in perturbative QCD. We consider a Higgs boson decaying into bottom (charm) quark pairs via Yukawa interaction and into gluons via an effective vertex in the limit of infinite top quark mass. We present results for the two decay modes separately, highlighting relevant differences in the differential distributions, and for the sum of all decay channels, including a comparison between different choices of the Durham (or $k_T$) jet resolution parameter.

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arXiv2025

The Thrust Distribution at NNLO+NNLL in Higgs Decays to Quarks and Gluons

We present a calculation of the thrust distribution in Higgs decays to quarks and gluons, $H\to b\bar{b}$, $H\to c\bar{c}$, and $H\to gg$, including the resummation of large logarithmic corrections that arise in the two-particle limit at next-to-next-to-leading logarithmic (NNLL) accuracy, and match it to fixed-order results for three-particle decays at next-to-next-to-leading order (NNLO) in the strong coupling. The resummation is performed analytically within the ARES framework and combined with the fixed-order results using the logR matching technique. The fixed-order calculation is carried out numerically with the NNLOJET parton-level event generator, using the antenna subtraction method. We perform detailed cross-validation in the two-particle region, demonstrating that the expansion of the NNLL resummed result correctly reproduces the logarithmic structure of the fixed-order calculation to $\mathcal{O}(α_\mathrm{s}^3)$, up to a predictable N$^{3}$LL term at $\mathcal{O}(α_\mathrm{s}^3L)$. In addition to providing the first NNLO+NNLL accurate predictions for the thrust distribution in Higgs decays to quarks and gluons, we analytically extract the $\mathcal{O}(α_\mathrm{s}^2)$ hard-virtual correction $c_2$ and the $α_\mathrm{s}^3L$ term $G_{31}$ in both the $H\to q\bar{q}$ ($q=b,c$) and $H\to gg$ decay channels.

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arXiv2025

Precise Predictions for Event Shapes in Hadronic Higgs Decays

We present NNLO QCD predictions for a wide range of event-shape observables in hadronic Higgs decays, taking into account the two dominant decay modes $H\to gg$ and $H\to b\bar{b}$. Specifically, we consider the six classical event shapes thrust, heavy jet mass, $C$-parameter, total and wide jet broadening, and the three-jet resolution $y_{23}$ in the Durham algorithm. We also present results for the soft-drop variant of thrust. Decays of the Higgs boson to two gluons are treated in the heavy-top limit, whereas decays to a bottom-quark pair are mediated by a non-vanishing Yukawa coupling, despite considering kinematically massless quarks. Our results highlight the importance of NNLO QCD corrections in the calculation of event-shape observables and provide means to quantify the intrinsic difference between the two Higgs decay modes.

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arXiv2025

Jet rates in Higgs boson decay at third order in QCD

We compute the production rates for two, three, four and five jets in the hadronic decay of a Higgs boson in its two dominant decay modes to bottom quarks and gluons to third order in the QCD coupling constant. The five-, four- and three-jet rates are obtained from a next-to-next-to-leading order (NNLO) calculation of Higgs decay to three jets, while the two-jet rate is inferred at next-to-next-to-next-to-leading order (N$^3$LO) from the inclusive decay rate. Our results show distinct differences in the dependence of the jet rates on the jet resolution parameter between the two decay modes, supporting the aim of discriminating different Higgs boson decay channels via classic QCD observables.

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arXiv2025

Precise Determination of the Strong Coupling Constant from Dijet Cross Sections up to the Multi-TeV Range

We determine the value of the strong coupling $α_\text{s}$ and study its running over a wide range of scales as probed by the dijet production process at hadron colliders, based on an NNLO QCD analysis of LHC dijet data. From a large subset of these data a value of $α_\text{s} (m_\text{Z}) = 0.1178 \pm 0.0022$ is obtained for the strong coupling at the scale of the Z-boson mass $m_\text{Z}$, using the invariant mass of the dijet system to select the scale where $α_\text{s}$ is probed. The combination of different data sets enhances the reach and precision of the analysis in the mutli-TeV range and allows for the first determination of $α_\text{s}$ up to scales of 7 TeV. Complementing the LHC data with dijet cross sections measured at the HERA electron-proton collider, the kinematic range is extended to test the running of the strong coupling towards smaller scales. Our results exhibit excellent agreement with predictions based on the renormalization group equation of QCD, and represent a comprehensive test of the asymptotic behavior of QCD, spanning more than three orders of magnitude in energy scale.

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arXiv2025

EERAD3 version 2: QCD corrections in hadronic colour-singlet decays

We present a major update of the publicly available EERAD3 package to calculate perturbative corrections in the strong coupling in hadronic Higgs and $Z$-boson decays. We describe the theoretical framework underlying the numerical implementation and provide a guide to the usage of the program.

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arXiv2024

QCD predictions for vector boson plus hadron production at the LHC

The identification of a hadron in the final state of hadron-collider events that feature a leptonically decaying vector boson can provide essential information on the parton content of the colliding protons. Moreover, the study of hadrons inside jets can provide deeper insights into the fragmentation dynamics. We provide theoretical predictions for specific observables involving either the production of a $Z$ boson in association with light charged hadrons inside a jet or the production of a $W$ boson together with a charmed hadron. We present results for various fragmentation functions and compare our predictions with measurements by LHCb and ATLAS at $\sqrt{s}=13$ TeV. Our predictions are obtained using the antenna subtraction formalism which has been extended to cope with infrared singularities associated to the fragmentation processes in a hadron-collider environment at NLO accuracy.

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arXiv2024

NLO+NLL' accurate predictions for three-jet event shapes in hadronic Higgs decays

We present resummed predictions at next-to-leading logarithmic accuracy matched to the exact next-to-leading order results for a set of classical event-shape observables in hadronic Higgs decays, i.e., for the channels $H\to gg$ and $H\to b\bar{b}$. We furthermore consider soft-drop grooming of the hadronic final states and derive corresponding $\text{NLO}+\text{NLL}^\prime$ predictions for the groomed thrust observable. Differences in the QCD radiation pattern of gluon- and quark-initiated final states are imprinted in the event-shape distributions, offering separation power for the two decay channels. In particular, we show that ungroomed event shapes in $H\to gg$ decays develop a considerably harder spectrum than in $H\to b\bar b$ decays. We highlight that soft-drop grooming can substantially alter this behaviour, unless rather inclusive grooming parameters are chosen.

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arXiv2024

Four-jet event shapes in hadronic Higgs decays

We present next-to-leading order perturbative QCD predictions for four-jet-like event-shape observables in hadronic Higgs decays. To this end, we take into account two Higgs-decay categories: involving either the Yukawa-induced decay to a $b\bar{b}$ pair or the loop-induced decay to two gluons via an effective Higgs-gluon-gluon coupling. We present results for distributions related to the event-shape variables thrust minor, light-hemisphere mass, narrow jet broadening, $D$-parameter, and Durham four-to-three-jet transition variable. For each of these observables we study the impact of higher-order corrections and compare their size and shape in the two Higgs-decay categories. We find large NLO corrections with a visible shape difference between the two decay modes, leading to a significant shift of the peak in distributions related to the $H\to gg$ decay mode.

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arXiv2024

A comparative study of flavour-sensitive observables in hadronic Higgs decays

Jet production from hadronic Higgs decays at future lepton colliders will have significantly different phenomenological implications than jet production via off-shell photon and $Z$-boson decays, owing to the fact that Higgs bosons decay to both pairs of quarks and gluons. We compute observables involving flavoured jets in hadronic Higgs decays to three partons at Born level including next-to-leading order corrections in QCD (i.e up to $\mathcal{O}(α_\mathrm{S}^2))$. The calculation is performed in the framework of an effective theory in which the Higgs boson couples directly to gluons and massless $b$-quarks retaining a non-vanishing Yukawa coupling. For the energy of the leading and subleading flavoured jet, the angular separation and the invariant mass of the leading $b$-$\bar{b}$ pair, we contrast the results obtained in both Higgs decay categories and using either of the infrared-safe flavoured jet algorithms flavour-$k_\mathrm{T}$ and flavour-dressing.

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arXiv2022

QCD Predictions for Event-Shape Distributions in Hadronic Higgs Decays

We study the six classical event-shape observables in hadronic Higgs decays at next-to-leading order in QCD. To this end, we consider the decay of on-shell Higgs bosons to three partons, taking into account both the Yukawa-induced decay to $\mathrm{b}$-quark pairs and the loop-induced decay to two gluons via an effective Higgs-gluon coupling. The results are discussed with a particular focus on the discriminative power of event shapes regarding these two classes of processes.

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arXiv2021

Fiducial distributions in Higgs and Drell-Yan production at N$^3$LL+NNLO

The perturbative description of certain differential distributions across a wide kinematic range requires the matching of fixed-order perturbation theory with resummation of large logarithmic corrections to all orders. We present precise matched predictions for transverse-momentum distributions in Higgs boson (H) and Drell-Yan pair (DY) production as well as for the closely related ${ϕ^{*}_η}$ distribution at the LHC. The calculation is exclusive in the Born kinematics, and allows for arbitrary fiducial selection cuts on the decay products of the colour singlets, which is of primary relevance for experimental analyses. Our predictions feature very small residual scale uncertainties and display a good convergence of the perturbative series. A comparison of the predictions for DY observables to experimental data at 8 TeV shows a very good agreement within the quoted errors.

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arXiv2020

Phenomenology of NNLO jet production at the LHC and its impact on parton distributions

We present a systematic investigation of jet production at hadron colliders from a phenomenological point of view, with the dual aim of providing a validation of theoretical calculations and guidance to future determinations of parton distributions (PDFs). We account for all available inclusive jet and dijet production measurements from ATLAS and CMS at 7 and 8 TeV by including them in a global PDF determination, and comparing to theoretical predictions at NNLO QCD supplemented by electroweak (EW) corrections. We assess the compatibility of the PDFs, specifically the gluon, obtained before and after inclusion of the jet data. We compare the single-inclusive jet and dijet observables in terms of perturbative behaviour upon inclusion of QCD and EW corrections, impact on the PDFs, and global fit quality. In the single-inclusive case, we also investigate the role played by different scale choices and the stability of the results upon changes in modelling of the correlated experimental systematics.

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arXiv2019

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

We present accurate QCD predictions for the transverse momentum pT spectrum of electroweak gauge bosons at the LHC for 13 TeV collisions, based on a consistent combination of a NNLO calculation at large pT and N3LL resummation in the small pT 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 pT 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.

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