arXiv subjects

Matteo Marcoli

Publications and source records attributed to Matteo Marcoli.

At least 19 recordsLinked to original sources

arXiv2026

LHC Constraints on Resonant Kaluza-Klein Gravitons

The signature prediction of extra-dimensional theories is the appearance of a tower of massive gravitons. In this work, we study the constraints on resonant heavy spin-2 particles at the Large Hadron Collider (LHC), with focus on the entire tower of gravitons, beyond the traditional single-resonance analysis. Since several states of the tower can lie within the same accessible mass window, the combined signal is enhanced, and the resulting constraints can be significantly stronger than those obtained from a single resonance alone. We first update the current constraints on single graviton searches stemming from diphoton and dilepton data from ATLAS and CMS, using datasets collected above $\sim 200\,{\rm GeV}$, and then consider the impact on the bounds of the full tower of states for different extra-dimensional scenarios. This allows us to extend the reach of current searches to lower mass regions than typically considered, paving the way for future analyses by experimental collaborations.

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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

Recent progress in antenna subtraction at NNLO and N$^3$LO

In this contribution I will review recent developments in the antenna subtraction method for higher-order calculations in QCD. In particular, I will illustrate the definition and applications of generalised antenna functions for final-state radiation at NNLO and present the first N$^3$LO differential calculation performed entirely with antenna subtraction for jet production at electron-positron colliders. Finally, I will discuss how the extension of generalised antenna functions at N$^3$LO will allow to tackle more complicated processes at this perturbative order.

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arXiv2026

The Four-Jet Rate in Electron-Positron Annihilation at Order $\alpha_s^4$

We compute for the first time the production rate for four jets in electron-positron annihilation at next-to-next-to-leading order. Our calculation exhibits the highest final-state jet multiplicity considered at this perturbative accuracy to date. The cancellation of infrared singularities is achieved in the antenna subtraction scheme, relying particularly on generalized antenna functions. The evaluation of the two-loop virtual corrections is enabled by the construction of a new basis of transcendental special functions tailored to four-particle decay kinematics. Our results are compared with LEP data, finding improved agreement with respect to the next-to-leading order calculation. In the region where perturbative predictions are most reliable, we observe a significant reduction of theory uncertainties, which now fall below the experimental ones.

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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 $\mathcal{O}(\alpha_\mathrm{s}^3)$, up to a predictable N$^{3}$LL term at $\mathcal{O}(\alpha_\mathrm{s}^3L)$. 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 $\mathcal{O}(\alpha_\mathrm{s}^2)$ hard-virtual correction $c_2$ and the $\alpha_\mathrm{s}^3L$ 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

Phase-space sectors for ordered momentum mappings in local subtraction up to N$^3$LO

Ordered momentum mappings present optimal convergence in soft and collinear configurations and are particularly suitable for the numerical implementation of local subtraction schemes. However, ordered mappings cannot be directly applied in the presence of multiple unordered emissions, which typically appear beyond the leading-colour approximation. A possible solution consists in separating individual singularities at the level of local counterterms by means of partial fractioning, which can become cumbersome at higher orders and introduce large cancellations in intermediate steps of the calculations. We present a simple decomposition of the phase space into sectors to isolate classes of infrared configurations which can be addressed with a specific ordered momentum mapping. With such decomposition, the singularities of any matrix element can be subtracted with ordered mappings, without the need of partial fractioning. We illustrate the required phase-space sectors for up to three unordered emissions and discuss applications in the context of the antenna subtraction method. The mapping algorithm described here has been recently employed for the first differential N$^3$LO of jet production at electron-positron colliders.

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arXiv2025

Jet production at electron-positron colliders at next-to-next-to-next-to-leading order in QCD

We present the first application of antenna subtraction at next-to-next-to-next-to-leading order (N$^3$LO) in QCD by computing fully differential predictions for two-jet production at electron-positron colliders. We illustrate the structure of the infrared counterterms and provide results for the N$^3$LO correction to the two-jet production rate and to the leading-jet energy. Our work constitutes the first direct calculation of jet production at electron-positron colliders at N$^3$LO and represents the first step in tackling arbitrary processes with jets at this perturbative order.

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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 Predictions for Event Shapes in Diphoton Production at the LHC

Photon pair production is an important benchmark process at the LHC, entering Higgs boson studies and new physics searches. It has been measured to high accuracy, allowing for detailed studies of event shapes in diphoton final states. To enable precision physics with diphoton event shapes, we compute the second-order QCD corrections, ${\cal O} (\alpha_s^3)$, to them and study their phenomenological impact.

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arXiv2024

Generalised Antenna Functions for Higher-Order Calculations

In this paper we discuss the definition, the construction and the implementation of \textit{generalised antenna functions} for final-state radiation up to Next-to-Next-to-Leading Order (NNLO) in QCD. Generalised antenna functions encapsulate the singular behaviour of unresolved emissions when these occur within multiple hard radiators and not just two of them, as for traditional antenna functions. The construction of such objects is possible thanks to the recently proposed algorithm for building \textit{idealised antenna functions} from a target set of infrared limits. Generalised antenna functions bring major simplifications in the assemblage of subtraction terms in the context of the antenna scheme at NNLO and beyond, as well as a substantial computational speedup of higher-order calculations. We discuss in detail the improvements on the formal and practical side for the computation of the NNLO correction to three-jet production at electron-positron colliders, providing a thorough numerical validation of the newly proposed scheme. For this calculation one can expect almost an order of magnitude speedup with respect to the original implementation.

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arXiv2024

Antenna subtraction for processes with identified particles at hadron colliders

Collider processes with identified hadrons in the final state are widely studied in view of determining details of the proton structure and of understanding hadronization. Their theory description requires the introduction of fragmentation functions, which parametrise the transition of a produced parton into the identified hadron. To compute higher-order perturbative corrections to these processes requires a subtraction method for infrared singular configurations. We extend the antenna subtraction method to hadron fragmentation processes in hadronic collisions up to next-to-next-to-leading order (NNLO) in QCD by computing the required fragmentation antenna functions in initial-final kinematics. The integrated antenna functions retain their dependence on the momentum fractions of the incoming and fragmenting partons.

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arXiv2023

Radiation from a gluon-gluino colour-singlet dipole at N$^3$LO

We compute the quantum chromodynamics (QCD) corrections to the decay of a neutralino to gluinos and partons at next-to-next-to-next-to-leading order (N$^3$LO) in the strong coupling constant $\alpha_s$, integrated separately over the phase-space of two, three, four or five particles in the final state. The resulting matrix elements are related to the quark-gluon antenna functions, completing the set of integrated antenna functions in final-final kinematics required for the extension of the antenna subtraction scheme to N$^3$LO. For a model with massless partons (quarks and gluons) and an arbitrary number of adjoint fermions, we obtained the following new results to $\mathcal{O}(\alpha_s^3)$: the inclusive cross section for the decay of a neutralino, the renormalization of the effective coupling of a neutralino to a gluino and gluon(s), the gluino collinear anomalous dimension, the gluino contribution to the parton collinear anomalous dimensions and the neutralino-gluino-gluon(s) vertex form factors. A special case of this model is the $\mathcal{N}=1$ super Yang-Mills theory, where we can relate some of our findings to known results.

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arXiv2023

N$^3$LO Antenna Functions for Final-State Radiation

We discuss recent progress in the calculation of integrated antenna functions for final-state radiation at N$^3$LO in QCD. Antenna functions are directly extracted from physical matrix elements for the decay of a colour-singlet state into partons. In order to compute their integrated counterparts, which are necessary ingredients for fixed-order calculations in QCD, each allowed final state has to be individually integrated over the inclusive phase space of the unresolved radiation. We analytically integrated two-, three-, four- and five-particle final-state matrix elements for the decay of a virtual photon and a Higgs boson into partons, considering up to third-order corrections in the strong coupling constant $\alpha_s$. The integration over the inclusive phase space is performed relying on well-established reverse unitarity and IBP reduction techniques. We conclude with preliminary comments about the structure of N$^3$LO subtraction terms in the context of the antenna subtraction method.

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arXiv2023

The parton-level structure of Higgs decays to hadrons at N$^3$LO

We present the quantum chromodynamics (QCD) corrections for Higgs boson decays to hadronic final states at next-to-next-to-next-to-leading order (N$^3$LO) in the strong coupling constant $\alpha_s$. In particular, we consider the Higgs boson decay to massless bottom quarks and the Higgs boson decay to a pair of gluons in the limit of a heavy top quark. The tree-level five-parton, the one-loop four-parton, the two-loop three-parton, and the three-loop two-parton matrix elements are integrated separately over the inclusive phase space and classified by partons appearing in the final state and by colour structure. As a check, we reproduce known results for the hadronic $R$-ratios at N$^3$LO. We study patterns of infrared singularity cancellation within the colour layers of the integrated expressions and observe an agreement in the highest trascendental weight terms in the decay of different colour singlets to quarks. We anticipate that our result will be an essential ingredient for the formulation of N$^3$LO subtraction schemes.

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arXiv2022

The parton-level structure of $e^+e^-$ to 2 jets at N$^3$LO

We investigate the quantum chromodynamics (QCD) corrections to hadronic final states in electron-positron collisions at $\mathcal{O}(\alpha_s^3)$ in the strong coupling constant $\alpha_s$. Namely, we analytically compute the total cross section for this process by separately integrating the tree-level five-parton, the one-loop four-parton, the two-loop three-parton, and the three-loop two-parton matrix elements over the respective phase space. All the contributions to the calculation are treated in a common framework whereby phase space integrals are expressed as physical cuts of the four-loop two-point function. We check the cancellation of infrared poles at all colour levels and we reproduce the known result for the $R$-ratio at order $\alpha_s^3$.

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