Massimiliano Grazzini
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
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Massimiliano Grazzini has a total of 232 co-authors. Here are the top co-authors by number of shared publications:
- Stefan Kallweit
Universität Zürich
39 shared publications - Daniel de Florian
UNSAM - Universidad Nacional de San Martin, International Center for Advanced Studies (ICAS) and Instituto de Ciencias Físicas (ICIFI), Buenos Aires, Argentina
29 shared publications Stefano Catani
INFN, Sezione di Firenze, Sesto Fiorentino, Italy
19 shared publications- Stefano Catani
INFN, Sezione di Firenze and Dipartimento di Fisica e Astronomia, Università di Firenze, Florence, Italy
18 shared publications - Marius Wiesemann
Max-Planck-Institut für Physik
17 shared publications - Giancarlo Ferrera
Universitá di Milano and INFN, Sezione di Milano
15 shared publications
Latest Publications
- Open Access
- 25 August 2026
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2026 (8) , 196
Non-factorisable electroweak virtual corrections to single-resonant processes
A bstract: We consider electroweak (EW) virtual corrections to 2 → 2 fermion scattering processes mediated by a vector boson V ( V = W ± , Z ) in the pole approximation. As is well known, the computation can be organised into factorisable and non-factorisable contributions. The factorisable corrections can be computed by evaluating the (polarised) EW form factor of the vector boson at the relevant perturbative order. The non-factorisable corrections are instead driven by soft-photon exchanges between the initial- and final-state fermions and/or the resonance. We perform an explicit two-loop computation to show that, once the heavy degrees of freedom are properly decoupled, such non-factorisable corrections can be expressed as an iteration of the one-loop result, plus a new contribution due to (light) fermion loops. The final two-loop result, which can be expected on general grounds from soft-photon factorisation, is shown to hold exactly in dimensional regularisation and is peculiar to the exchange of a single resonance. We discuss its extension to all perturbative orders.
- 25 August 2026
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2026 (8) , 196
Open AccessNon-factorisable electroweak virtual corrections to single-resonant processes
A bstract: We consider electroweak (EW) virtual corrections to 2 → 2 fermion scattering processes mediated by a vector boson V ( V = W ± , Z ) in the pole approximation. As is well known, the computation can be organised into factorisable and non-factorisable contributions. The factorisable corrections can be computed by evaluating the (polarised) EW form factor of the vector boson at the relevant perturbative order. The non-factorisable corrections are instead driven by soft-photon exchanges between the initial- and final-state fermions and/or the resonance. We perform an explicit two-loop computation to show that, once the heavy degrees of freedom are properly decoupled, such non-factorisable corrections can be expressed as an iteration of the one-loop result, plus a new contribution due to (light) fermion loops. The final two-loop result, which can be expected on general grounds from soft-photon factorisation, is shown to hold exactly in dimensional regularisation and is peculiar to the exchange of a single resonance. We discuss its extension to all perturbative orders.
- Open Access
- 2 April 2026
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2026 (4)
Jet production at NNLO: exploring a new scheme
A bstract: We consider dijet production in e + e − collisions and in $$ H\to b\overline{b} $$ decays at next-to-next-to-leading order (NNLO) in perturbative QCD. A new non-local subtraction scheme is applied, for the first time, to obtain the fully differential cross section for these benchmark processes. We discuss and explicitly evaluate the perturbative ingredients needed in the computation, and we compare the performance of different slicing variables to obtain the NNLO corrections.- 2 April 2026
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2026 (4)
Open AccessJet production at NNLO: exploring a new scheme
A bstract: We consider dijet production in e + e − collisions and in $$ H\to b\overline{b} $$ decays at next-to-next-to-leading order (NNLO) in perturbative QCD. A new non-local subtraction scheme is applied, for the first time, to obtain the fully differential cross section for these benchmark processes. We discuss and explicitly evaluate the perturbative ingredients needed in the computation, and we compare the performance of different slicing variables to obtain the NNLO corrections. - Open Access
- 5 February 2026
- Published by Springer Nature in The European Physical Journal C
- Vol. 86 (2)
NNLO QCD predictions for $W\gamma \gamma $ production at the LHCTriboson production processes play a crucial role in probing the electroweak sector of the Standard Model, as they involve quartic gauge-boson couplings already at the tree level. With these measurements entering the precision era at the Large Hadron Collider (LHC), accurate theoretical predictions become indispensable. We present the computation of the next-to-next-to-leading-order (NNLO) QCD radiative corrections to the production of a W boson in association with two photons ( $$W\gamma \gamma $$ ) at the LHC. The calculation is exact, except for the finite part of the two-loop contribution, which is included in the leading-colour approximation. Predictions for the fiducial cross section and selected kinematic distributions are provided at a centre-of-mass energy of $$\sqrt{s}=13$$ TeV, under standard experimental selection cuts. In line with observations for other multiboson processes involving direct photons, we find sizable NNLO corrections that enhance the next-to-leading-order predictions by about $$23\%$$ , with residual perturbative uncertainties that can be roughly estimated to be at the $$5\%$$ level.- 5 February 2026
- Published by Springer Nature in The European Physical Journal C
- Vol. 86 (2)
Open AccessNNLO QCD predictions for $W\gamma \gamma $ production at the LHCTriboson production processes play a crucial role in probing the electroweak sector of the Standard Model, as they involve quartic gauge-boson couplings already at the tree level. With these measurements entering the precision era at the Large Hadron Collider (LHC), accurate theoretical predictions become indispensable. We present the computation of the next-to-next-to-leading-order (NNLO) QCD radiative corrections to the production of a W boson in association with two photons ( $$W\gamma \gamma $$ ) at the LHC. The calculation is exact, except for the finite part of the two-loop contribution, which is included in the leading-colour approximation. Predictions for the fiducial cross section and selected kinematic distributions are provided at a centre-of-mass energy of $$\sqrt{s}=13$$ TeV, under standard experimental selection cuts. In line with observations for other multiboson processes involving direct photons, we find sizable NNLO corrections that enhance the next-to-leading-order predictions by about $$23\%$$ , with residual perturbative uncertainties that can be roughly estimated to be at the $$5\%$$ level. - Open Access
- 12 November 2025
- Published by Springer Nature in The European Physical Journal C
- Vol. 85 (11) , 1-11
The quark jet function for $k_T$-like variables in NNLO QCDThe precise description of jet processes requires observables capable of efficiently capturing the dynamics of the energy flow in hadronic final states. We consider a class of transverse-momentum like resolution variables that smoothly describe the $$n+1$$ to n jet transition in multi-jet processes. We discuss a general method for the computation of the corresponding quark jet function at next-to-next-to-leading order in perturbative QCD. Rapidity divergences are regulated by using a time-like auxiliary vector. We present explicit results for a variant of $$y_{23}$$ in the E -scheme and in the WTA scheme.- 12 November 2025
- Published by Springer Nature in The European Physical Journal C
- Vol. 85 (11) , 1-11
Open AccessThe quark jet function for $k_T$-like variables in NNLO QCDThe precise description of jet processes requires observables capable of efficiently capturing the dynamics of the energy flow in hadronic final states. We consider a class of transverse-momentum like resolution variables that smoothly describe the $$n+1$$ to n jet transition in multi-jet processes. We discuss a general method for the computation of the corresponding quark jet function at next-to-next-to-leading order in perturbative QCD. Rapidity divergences are regulated by using a time-like auxiliary vector. We present explicit results for a variant of $$y_{23}$$ in the E -scheme and in the WTA scheme. - Open Access
- 23 October 2025
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2025 (10) , 1-85
Towards NNLO QCD predictions for off-shell top-quark pair production and decays
A bstract: We consider QCD radiative corrections to $$ {W}^{+}{W}^{-}b\overline{b} $$ production with leptonic decays and massive bottom quarks at the LHC. We perform an exact next-to-leading order (NLO) calculation within the q T -subtraction formalism and validate it against an independent computation in the dipole subtraction scheme. Non-resonant and off-shell effects related to the top quarks and the leptonic decays of the W ± bosons are consistently included. We also consider the approximation in which the real-emission contribution is computed exactly while the virtual is evaluated in the double-pole approximation (DPA), which formally requires the inclusion of both factorisable and non-factorisable corrections. We evaluate such contributions and show that the DPA performs remarkably well at both the inclusive and differential levels. We then extend our calculation to the next-to-next-to-leading order (NNLO). All tree-level and one-loop amplitudes are evaluated exactly, while the missing two-loop virtual contribution is estimated using the DPA. The factorisable two-loop corrections are explicitly computed by relying on available results for the polarised two-loop on-shell top-quark pair production amplitudes and the corresponding top-quark decays. The non-factorisable contributions are inferred by exploiting the cancellation of logarithmic singularities in the Γ t → 0 limit through an on-shell matching procedure. The NNLO corrections for the inclusive cross section are found to increase the NLO prediction by approximately 11%, with a numerical uncertainty that is conservatively estimated to be below the 2% level — significantly smaller than the 5% residual perturbative uncertainties.- 23 October 2025
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2025 (10) , 1-85
Open AccessTowards NNLO QCD predictions for off-shell top-quark pair production and decays
A bstract: We consider QCD radiative corrections to $$ {W}^{+}{W}^{-}b\overline{b} $$ production with leptonic decays and massive bottom quarks at the LHC. We perform an exact next-to-leading order (NLO) calculation within the q T -subtraction formalism and validate it against an independent computation in the dipole subtraction scheme. Non-resonant and off-shell effects related to the top quarks and the leptonic decays of the W ± bosons are consistently included. We also consider the approximation in which the real-emission contribution is computed exactly while the virtual is evaluated in the double-pole approximation (DPA), which formally requires the inclusion of both factorisable and non-factorisable corrections. We evaluate such contributions and show that the DPA performs remarkably well at both the inclusive and differential levels. We then extend our calculation to the next-to-next-to-leading order (NNLO). All tree-level and one-loop amplitudes are evaluated exactly, while the missing two-loop virtual contribution is estimated using the DPA. The factorisable two-loop corrections are explicitly computed by relying on available results for the polarised two-loop on-shell top-quark pair production amplitudes and the corresponding top-quark decays. The non-factorisable contributions are inferred by exploiting the cancellation of logarithmic singularities in the Γ t → 0 limit through an on-shell matching procedure. The NNLO corrections for the inclusive cross section are found to increase the NLO prediction by approximately 11%, with a numerical uncertainty that is conservatively estimated to be below the 2% level — significantly smaller than the 5% residual perturbative uncertainties. - Open Access
- 13 August 2025
- Published by Stichting SciPost in SciPost Physics Community Reports
- p. 010
State-of-the-art cross sections for $t\bar t H$: NNLO predictions matched with NNLL resummation and EW corrections
We present new, state-of-the-art predictions for the associated production of the SM Higgs boson with top quarks, computed in accordance with the recommendations of the LHC Higgs Working Group. The NNLO QCD predictions, derived through suitable approximations of the two-loop virtual contribution, are supplemented with soft-gluon resummation up to NNLL accuracy. Two distinct resummation frameworks are employed – one based on direct QCD and the other on soft-collinear effective theory – and their features are compared in detail. These results are further combined with the complete-NLO corrections, yielding the most precise SM predictions for this process to date. The relevant sources of theoretical uncertainties are thoroughly estimated and discussed.
- 13 August 2025
- Published by Stichting SciPost in SciPost Physics Community Reports
- p. 010
Open AccessState-of-the-art cross sections for $t\bar t H$: NNLO predictions matched with NNLL resummation and EW corrections
We present new, state-of-the-art predictions for the associated production of the SM Higgs boson with top quarks, computed in accordance with the recommendations of the LHC Higgs Working Group. The NNLO QCD predictions, derived through suitable approximations of the two-loop virtual contribution, are supplemented with soft-gluon resummation up to NNLL accuracy. Two distinct resummation frameworks are employed – one based on direct QCD and the other on soft-collinear effective theory – and their features are compared in detail. These results are further combined with the complete-NLO corrections, yielding the most precise SM predictions for this process to date. The relevant sources of theoretical uncertainties are thoroughly estimated and discussed.
- Open Access
- 11 July 2025
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2025 (7) , 1-26
Mixed QCD-EW corrections to the neutral-current Drell-Yan process
A bstract: We report on the complete computation of the mixed QCD-electroweak corrections to the neutral-current Drell-Yan process. Our calculation holds in the entire range of dilepton invariant masses. We present phenomenological results for several kinematical distributions in the case of bare muons both in the resonant region and for high invariant masses. We also consider the forward-backward asymmetry, which is a key observable to measure the weak mixing angle. We finally extend our calculation to dressed leptons and compare our results in the massless limit to those available in the literature.
- 11 July 2025
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2025 (7) , 1-26
Open AccessMixed QCD-EW corrections to the neutral-current Drell-Yan process
A bstract: We report on the complete computation of the mixed QCD-electroweak corrections to the neutral-current Drell-Yan process. Our calculation holds in the entire range of dilepton invariant masses. We present phenomenological results for several kinematical distributions in the case of bare muons both in the resonant region and for high invariant masses. We also consider the forward-backward asymmetry, which is a key observable to measure the weak mixing angle. We finally extend our calculation to dressed leptons and compare our results in the massless limit to those available in the literature.
- Top Cited PapersOpen Access
- 25 March 2025
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2025 (3) , 1-43
Precise predictions for $ t\overline{t}H $ production at the LHC: inclusive cross section and differential distributionsWe present the first fully differential next-to-next-to-leading order (NNLO) QCD calculation for the production of a top-antitop quark pair in association with a Higgs boson $$ \left(t\overline{t}H\right) $$ at hadron colliders. The computation is exact, except for the finite part of the two-loop virtual contribution, which we estimate using two different methods that yield consistent results within their respective uncertainties. The first method relies on a soft-Higgs factorisation formula that we develop up to the three-loop order. The second is based on a high-energy expansion in the small top-mass limit. Combining the newly computed corrections with the complete set of next-to-leading order (NLO) QCD+EW results provides the most advanced perturbative prediction currently available at the LHC for both inclusive and differential $$ t\overline{t}H $$ cross sections. The uncertainties due to the missing exact two-loop contribution are conservatively estimated to be at the percent level, both for the total cross section and for most of the differential distributions, and therefore subleading compared to the residual perturbative uncertainties.- 25 March 2025
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2025 (3) , 1-43
Top Cited PapersOpen AccessPrecise predictions for $ t\overline{t}H $ production at the LHC: inclusive cross section and differential distributionsWe present the first fully differential next-to-next-to-leading order (NNLO) QCD calculation for the production of a top-antitop quark pair in association with a Higgs boson $$ \left(t\overline{t}H\right) $$ at hadron colliders. The computation is exact, except for the finite part of the two-loop virtual contribution, which we estimate using two different methods that yield consistent results within their respective uncertainties. The first method relies on a soft-Higgs factorisation formula that we develop up to the three-loop order. The second is based on a high-energy expansion in the small top-mass limit. Combining the newly computed corrections with the complete set of next-to-leading order (NLO) QCD+EW results provides the most advanced perturbative prediction currently available at the LHC for both inclusive and differential $$ t\overline{t}H $$ cross sections. The uncertainties due to the missing exact two-loop contribution are conservatively estimated to be at the percent level, both for the total cross section and for most of the differential distributions, and therefore subleading compared to the residual perturbative uncertainties. - Open Access
- 27 April 2024
- Published by Springer Nature in The European Physical Journal C
- Vol. 84 (4) , 1-12
Subleading power corrections for event shape variables in $e^+ e^-$ annihilationWe consider subleading power corrections to event shape variables in $$e^+e^-$$ collisions at the first order in the QCD coupling $$\alpha _{\textrm{S}}$$ . We start from the jettiness variable $$\tau _2$$ and the $$y_{23}$$ resolution variable for the $$k_T$$ jet clustering algorithm and we analytically compute the corresponding cumulative cross section. We investigate the origin of the different power suppressed contributions in the two-jet limit and trace it back to their different coverage of the phase space. We extend our analysis to the case of thrust and of the C-parameter, and we finally discuss a class of observables that depend on a continuous parameter giving different weight to central and forward emissions and we evaluate the corresponding subleading power corrections.- 27 April 2024
- Published by Springer Nature in The European Physical Journal C
- Vol. 84 (4) , 1-12
Open AccessSubleading power corrections for event shape variables in $e^+ e^-$ annihilationWe consider subleading power corrections to event shape variables in $$e^+e^-$$ collisions at the first order in the QCD coupling $$\alpha _{\textrm{S}}$$ . We start from the jettiness variable $$\tau _2$$ and the $$y_{23}$$ resolution variable for the $$k_T$$ jet clustering algorithm and we analytically compute the corresponding cumulative cross section. We investigate the origin of the different power suppressed contributions in the two-jet limit and trace it back to their different coverage of the phase space. We extend our analysis to the case of thrust and of the C-parameter, and we finally discuss a class of observables that depend on a continuous parameter giving different weight to central and forward emissions and we evaluate the corresponding subleading power corrections. - Open Access
- 28 December 2023
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2023 (12) , 1-44
Exploring slicing variables for jet processes
We consider the class of inclusive hadron collider processes in which one or more energetic jets are produced, possibly accompanied by colourless particles. We provide a general formulation of a slicing scheme for this class of processes, by identifying the various contributions that need to be computed up to next-to-leading order (NLO) in QCD perturbation theory. We focus on two novel observables, the one-jet resolution variable ∆Et and the n-jet resolution variable $$ {k}_T^{\textrm{ness}} $$ , and explicitly compute all the ingredients needed to carry out NLO computations using these variables. We contrast the behaviour of these variables when the slicing parameter becomes small. In the case of $$ {k}_T^{\textrm{ness}} $$ we also present results for the hadroproduction of multiple jets.- 28 December 2023
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2023 (12) , 1-44
Open AccessExploring slicing variables for jet processes
We consider the class of inclusive hadron collider processes in which one or more energetic jets are produced, possibly accompanied by colourless particles. We provide a general formulation of a slicing scheme for this class of processes, by identifying the various contributions that need to be computed up to next-to-leading order (NLO) in QCD perturbation theory. We focus on two novel observables, the one-jet resolution variable ∆Et and the n-jet resolution variable $$ {k}_T^{\textrm{ness}} $$ , and explicitly compute all the ingredients needed to carry out NLO computations using these variables. We contrast the behaviour of these variables when the slicing parameter becomes small. In the case of $$ {k}_T^{\textrm{ness}} $$ we also present results for the hadroproduction of multiple jets.