A. De Freitas

activity

19992026

most citedSupersymmetric Regularization, Two-Loop QCD Amplitudes and Coupling Shifts

204 citations · 1.4k across the 24 of their papers we have counts for

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hep-ph2026

Holonomic techniques for massive 3-loop form factors: the gluonic case

J. Blümlein, A. De Freitas, P. Marquard +2

Massive three-loop form factors for vector, axial-vector, scalar, and pseudoscalar currents are vital for precision collider phenomenology. Extending the quarkonic framework to the…

hep-ph2026

Analytic results on the massive three-loop form factors: gluonic contributions

J. Blümlein, A. De Freitas, P. Marquard +2

We compute the gluonic contributions to the three-loop heavy-quark form factors for the vector, axial-vector, scalar, and pseudoscalar currents. In the low-energy limit, $q^2/m^2 \…

hep-ph2024★ 12 cited

The non-first-order-factorizable contributions to the three-loop single-mass operator matrix elements $A_{Q g}^{(3)}$ and $Δ A_{Q g}^{(3)}$

J. Ablinger, A. Behring, J. Blümlein +4

The non-first-order-factorizable contributions (The terms 'first-order-factorizable contributions' and 'non-first-order-factorizable contributions' have been introduced and discuss…

hep-ph2023★ 18 cited

The first-order factorizable contributions to the three-loop massive operator matrix elements $A_{Q g}^{(3)}$ and $Δ A_{Q g}^{(3)}$

J. Ablinger, A. Behring, J. Blümlein +4

The unpolarized and polarized massive operator matrix elements $A_{Q g}^{(3)}$ and $Δ A_{Q g}^{(3)}$ contain first-order factorizable and non-first-order factorizable contributions in…

hep-ph2022★ 16 cited

$O (α_{s}^{2}$ ) Polarized Heavy Flavor Corrections}to Deep-Inelastic Scattering at $Q^{2} ≫ m^{2}$

I. Bierenbaum, J. Blümlein, A. De Freitas +3

We calculate the quarkonic $O (α_{s}^{2})$ massive operator matrix elements $Δ A_{Q g} (N), Δ A_{Qq}^{PS} (N)$ and $Δ A_{q q, Q}^{NS} (N)$ for the twist--2 operators and the associated h…

hep-ph2022★ 23 cited

The Unpolarized and Polarized Single-Mass Three-Loop Heavy Flavor Operator Matrix Elements $A_{g g, Q}$ and $Δ A_{g g, Q}$

J. Ablinger, A. Behring, J. Blümlein +3

We calculate the gluonic massive operator matrix elements in the unpolarized and polarized cases, $A_{g g, Q} (x, μ^{2})$ and $Δ A_{g g, Q} (x, μ^{2})$ , at three-loop order for a single mass. T…

hep-ph2021★ 10 cited

The QED Initial State Corrections to the Forward-Backward Asymmetry of $e^{+} e^{-} \to γ^{} / Z^{0 }$ to Higher Orders

J. Blümlein, A. De Freitas, K. Schönwald

The QED initial state corrections are calculated to the forward-backward asymmetry for $e^{+} e^{-} \to γ^{*} / Z^{0}^{*}$ in the leading logarithmic approximation to $O (α^{6} L^{6})$ e…

hep-ph2020★ 25 cited

The $O (α^{2})$ Initial State QED Corrections to $e^{+} e^{-} \to γ^{} / Z_{0}^{}$

J. Blümlein, A. De Freitas, C. Raab +1

We calculate the complete $O (α^{2})$ initial state radiation corrections to $e^{+} e^{-}$ annihilation into a neutral vector boson in a direct analytic computation without any approximat…

hep-ph2019

Revisiting the $O (α^{2})$ Initial State QED Corrections to $e^{+} e^{-}$ Annihilation into a Neutral Boson

J. Blümlein, A. De Freitas, C. G. Raab +1

At $e^{+} e^{-}$ colliders the QED--initial state radiation forms a large part of the radiative corrections. Their precise and fast evaluation is an essential asset for the experime…

hep-ph2019★ 16 cited

The effects of $O (α^{2})$ initial state QED corrections to $e^{+} e^{-} \to γ^{} / Z^{}$ at very high luminosity colliders

J. Blümlein, A. De Freitas, C. G. Raab +1

We present numerical results on the recently completed $O (α^{2})$ initial state corrections to the process $e^{+} e^{-} \to γ^{*} / Z^{*}$ , which is a central process at past and future…

hep-ph2019★ 17 cited

The unpolarized two-loop massive pure singlet Wilson coefficients for deep-inelastic scattering

J. Blümlein, A. De Freitas, C. G. Raab +1

We calculate the massive two--loop pure singlet Wilson coefficients for heavy quark production in the unpolarized case analytically in the whole kinematic region and derive the thr…

hep-ph2019★ 28 cited

The $O (α^{2})$ Initial State QED Corrections to $e^{+} e^{-}$ Annihilation to a Neutral Vector Boson Revisited

J. Blümlein, A. De Freitas, C. G. Raab +1

We calculate the non-singlet, the pure singlet contribution, and their interference term, at $O (α^{2})$ due to electron-pair initial state radiation to $e^{+} e^{-}$ annihilation into a…

hep-ph2016★ 62 cited

The Complete $O (α_{s}^{2})$ Non-Singlet Heavy Flavor Corrections to the Structure Functions $g_{1, 2}^{e p} (x, Q^{2})$ , $F_{1, 2, L}^{e p} (x, Q^{2})$ , $F_{1, 2, 3}^{ν (ν ˉ)} (x, Q^{2})$ and the Associated Sum Rules

Johannes Blümlein, Giulio Falcioni, Abilio De Freitas

We calculate analytically the flavor non-singlet $O (α_{s}^{2})$ massive Wilson coefficients for the inclusive neutral current non-singlet structure functions $F_{1, 2, L}^{e p} (x, Q^{2})$ an…

hep-ph2014

3-loop heavy flavor Wilson coefficients in deep-inelastic scattering

J. Ablinger, A. Behring, J. Blümlein +7

We present our most recent results on the calculation of the heavy flavor contributions to deep-inelastic scattering at 3-loop order in the large $Q^{2}$ limit, where the heavy flavo…

hep-ph2014★ 67 cited

The Logarithmic Contributions to the O(α_s^3) Asymptotic Massive Wilson Coefficients and Operator Matrix Elements in Deeply Inelastic Scattering

A. Behring, I. Bierenbaum, J. Blümlein +3

We calculate the logarithmic contributions to the massive Wilson coefficients for deep-inelastic scattering in the asymptotic region $Q^{2} ≫ m^{2}$ to 3-loop order in the fixed-flav…

hep-ph2011★ 1 cited

Two-loop operator matrix elements for massive fermionic local twist-2 operators in QED

J. Blümlein, A. De Freitas, W. L. van Neerven

We describe the calculation of the two--loop massive operator matrix elements with massive external fermions in QED. We investigate the factorization of the $O (α^{2})$ initial state…

hep-ph2011★ 47 cited

Two-loop QED Operator Matrix Elements with Massive External Fermion Lines

Johannes Blümlein, Abilio De Freitas, Wilhelmus van Neerven

The two-loop massive operator matrix elements for the fermionic local twist--2 operators with external massive fermion lines in Quantum Electrodynamics (QED) are calculated up to t…

hep-ph2004★ 101 cited

Two-Loop Helicity Amplitudes for Quark-Quark Scattering in QCD and Gluino-Gluino Scattering in Supersymmetric Yang-Mills Theory

Abilio De Freitas, Zvi Bern

We present the two-loop QCD helicity amplitudes for quark-quark and quark-antiquark scattering. These amplitudes are relevant for next-to-next-to-leading order corrections to (pola…

hep-ph2003★ 106 cited

Two-Loop Helicity Amplitudes for Quark-Gluon Scattering in QCD and Gluino-Gluon Scattering in Supersymmetric Yang-Mills Theory

Z. Bern, A. De Freitas, L. Dixon

We present the two-loop QCD helicity amplitudes for quark-gluon scattering, and for quark-antiquark annihilation into two gluons. These amplitudes are relevant for next-to-next-to-…

hep-ph2002

Two-loop corrections to $g g \to γ γ$

Z. Bern, A. De Freitas, L. Dixon

An overview of the calculation of the two-loop helicity amplitudes for scattering of two gluons into two photons is presented. These matrix elements enter into the recent improved…

hep-ph2002★ 204 cited

Supersymmetric Regularization, Two-Loop QCD Amplitudes and Coupling Shifts

Z. Bern, A. De Freitas, L. Dixon +1

We present a definition of the four-dimensional helicity (FDH) regularization scheme valid for two or more loops. This scheme was previously defined and utilized at one loop. It am…

hep-ph2002★ 202 cited

Two-Loop Helicity Amplitudes for Gluon-Gluon Scattering in QCD and Supersymmetric Yang-Mills Theory

Zvi Bern, Abilio De Freitas, Lance Dixon

We present the two-loop helicity amplitudes for the scattering of two gluons into two gluons in QCD, which are relevant for next-to-next-to-leading order corrections to jet product…

hep-ph2001★ 145 cited

QCD and QED Corrections to Light-by-Light Scattering

Z. Bern, A. De Freitas, L. Dixon +2

We present the QCD and QED corrections to the fermion-loop contributions to light-by-light scattering, gamma gamma to gamma gamma, in the ultrarelativistic limit where the kinemati…

hep-ph2001★ 173 cited

Two-Loop Amplitudes for Gluon Fusion into Two Photons

Z. Bern, A. De Freitas, L. Dixon

We present the two-loop matrix elements for the scattering of two gluons into two photons in QCD. These matrix elements will enter into improved estimates of the QCD background to…

Holonomic techniques for massive 3-loop form factors: the gluonic case

Analytic results on the massive three-loop form factors: gluonic contributions

The non-first-order-factorizable contributions to the three-loop single-mass operator matrix elements AQg(3)​ and ΔAQg(3)​

The first-order factorizable contributions to the three-loop massive operator matrix elements AQg(3)​ and ΔAQg(3)​

O(αs2​) Polarized Heavy Flavor Corrections}to Deep-Inelastic Scattering at Q2≫m2

The Unpolarized and Polarized Single-Mass Three-Loop Heavy Flavor Operator Matrix Elements Agg,Q​ and ΔAgg,Q​

The QED Initial State Corrections to the Forward-Backward Asymmetry of e+e−→γ∗/Z0∗ to Higher Orders

The O(α2) Initial State QED Corrections to e+e−→γ∗/Z0∗​

Revisiting the O(α2) Initial State QED Corrections to e+e− Annihilation into a Neutral Boson

The effects of O(α2) initial state QED corrections to e+e−→γ∗/Z∗ at very high luminosity colliders

The unpolarized two-loop massive pure singlet Wilson coefficients for deep-inelastic scattering

The O(α2) Initial State QED Corrections to e+e− Annihilation to a Neutral Vector Boson Revisited

The Complete O(αs2​) Non-Singlet Heavy Flavor Corrections to the Structure Functions g1,2ep​(x,Q2), F1,2,Lep​(x,Q2), F1,2,3ν(νˉ)​(x,Q2) and the Associated Sum Rules

3-loop heavy flavor Wilson coefficients in deep-inelastic scattering

The Logarithmic Contributions to the O(α_s^3) Asymptotic Massive Wilson Coefficients and Operator Matrix Elements in Deeply Inelastic Scattering

Two-loop operator matrix elements for massive fermionic local twist-2 operators in QED

Two-loop QED Operator Matrix Elements with Massive External Fermion Lines

Two-Loop Helicity Amplitudes for Quark-Quark Scattering in QCD and Gluino-Gluino Scattering in Supersymmetric Yang-Mills Theory

Two-Loop Helicity Amplitudes for Quark-Gluon Scattering in QCD and Gluino-Gluon Scattering in Supersymmetric Yang-Mills Theory

Two-loop corrections to gg→γγ

Supersymmetric Regularization, Two-Loop QCD Amplitudes and Coupling Shifts

Two-Loop Helicity Amplitudes for Gluon-Gluon Scattering in QCD and Supersymmetric Yang-Mills Theory

QCD and QED Corrections to Light-by-Light Scattering

Two-Loop Amplitudes for Gluon Fusion into Two Photons

The non-first-order-factorizable contributions to the three-loop single-mass operator matrix elements $A_{Q g}^{(3)}$ and $Δ A_{Q g}^{(3)}$

The first-order factorizable contributions to the three-loop massive operator matrix elements $A_{Q g}^{(3)}$ and $Δ A_{Q g}^{(3)}$

$O (α_{s}^{2}$ ) Polarized Heavy Flavor Corrections}to Deep-Inelastic Scattering at $Q^{2} ≫ m^{2}$

The Unpolarized and Polarized Single-Mass Three-Loop Heavy Flavor Operator Matrix Elements $A_{g g, Q}$ and $Δ A_{g g, Q}$

The QED Initial State Corrections to the Forward-Backward Asymmetry of $e^{+} e^{-} \to γ^{} / Z^{0 }$ to Higher Orders

The $O (α^{2})$ Initial State QED Corrections to $e^{+} e^{-} \to γ^{} / Z_{0}^{}$

Revisiting the $O (α^{2})$ Initial State QED Corrections to $e^{+} e^{-}$ Annihilation into a Neutral Boson

The effects of $O (α^{2})$ initial state QED corrections to $e^{+} e^{-} \to γ^{} / Z^{}$ at very high luminosity colliders

The $O (α^{2})$ Initial State QED Corrections to $e^{+} e^{-}$ Annihilation to a Neutral Vector Boson Revisited

The Complete $O (α_{s}^{2})$ Non-Singlet Heavy Flavor Corrections to the Structure Functions $g_{1, 2}^{e p} (x, Q^{2})$ , $F_{1, 2, L}^{e p} (x, Q^{2})$ , $F_{1, 2, 3}^{ν (ν ˉ)} (x, Q^{2})$ and the Associated Sum Rules

Two-loop corrections to $g g \to γ γ$