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Related papers: Two-loop form factors for diphoton production in q…

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We consider the diphoton production in hadronic collisions at the next-to-next-to-leading order (NNLO) in perturbative QCD, taking into account for the first time the full top quark mass dependence. We present the computation of the…

High Energy Physics - Phenomenology · Physics 2023-10-23 Federico Coro

We compute two-loop helicity amplitudes in QCD for diphoton production through quark- and gluon-initiated channels, accounting for a massive internal quark loop by keeping its full mass dependence. Using physical projectors, we directly…

High Energy Physics - Phenomenology · Physics 2025-02-06 Taushif Ahmed , Amlan Chakraborty , Ekta Chaubey , Mandeep Kaur

In this paper we consider the diphoton production in hadronic collisions at the next-to-next-to-leading order (NNLO) in perturbative QCD, taking into account for the first time the full top quark mass dependence up to two loops (full NNLO).…

High Energy Physics - Phenomenology · Physics 2023-12-01 Matteo Becchetti , Roberto Bonciani , Leandro Cieri , Federico Coro , Federico Ripani

We present an analytical calculation of the two-loop QCD corrections to the electromagnetic form factor of heavy quarks. The two-loop contributions to the form factor are reduced to linear combinations of master integrals, which are…

High Energy Physics - Phenomenology · Physics 2009-07-29 J. Gluza , A. Mitov , S. Moch , T. Riemann

We compute the two-loop QCD corrections to the heavy quark form factors in case of the vector, axial-vector, scalar and pseudo-scalar currents up to second order in the dimensional parameter $\epsilon = (4-D)/2$. These terms are required in…

High Energy Physics - Phenomenology · Physics 2018-05-30 J. Ablinger , A. Behring , J. Blümlein , G. Falcioni , A. De Freitas , P. Marquard , N. Rana , C. Schneider

We review on the calculation of the heavy-quark photo-production vector form factors, with the full dependence on the mass of the heavy-quark. The Feynman diagrams are evaluated within the dimensional regularization scheme and expressed in…

High Energy Physics - Phenomenology · Physics 2015-06-25 R. Bonciani

We compute squared matrix elements at next-to-next-to-leading order in perturbative quantum chromodynamics for the production of two or three (on- or off-shell) photons mediated via (light or heavy) quark loops. Our method handles all cases…

High Energy Physics - Phenomenology · Physics 2025-10-22 Dario Kermanschah , Matilde Vicini

We present the two-loop virtual QCD corrections to the production of heavy quarks in the quark--anti-quark--annihilation channel in the limit when all kinematical invariants are large compared to the mass of the heavy quark. Our result is…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Czakon , A. Mitov , S. Moch

I present the two-loop QCD corrections to the production of a massive quark-anti-quark pair in the massless quark-anti-quark annihilation channel. The result is obtained as a combination of a deep expansion in the mass around the high…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Czakon

We present the results for heavy quark form factors at two-loop order in perturbative QCD for different currents, namely vector, axial-vector, scalar and pseudo-scalar currents, up to second order in the dimensional regularization…

High Energy Physics - Phenomenology · Physics 2018-05-09 J. Ablinger , A. Behring , J. Blümlein , G. Falcioni , A. De Freitas , P. Marquard , N. Rana , C. Schneider

We present the analytical results for the two-loop form factors needed for $\chi_{Q,J}$ production and decay. We consider the two-loop corrections to the process $\gamma \gamma \leftrightarrow {^3 P_J^{[1]}}$, that has been known only…

High Energy Physics - Phenomenology · Physics 2025-06-10 Melih A. Ozcelik

We calculate the two-loop heavy quarkonium Hamiltonian within potential-NRQCD effective field theory in the non-annihilation channel. This calculation represents the first non-trivial step towards determining the N$^4$LO Hamiltonian in the…

High Energy Physics - Phenomenology · Physics 2024-11-15 Go Mishima , Yukinari Sumino , Hiromasa Takaura

We present the analytic calculation of the Master Integrals for the two-loop, non-planar topologies that enter the calculation of the amplitude for top-quark pair hadroproduction in the quark-annihilation channel. Using the method of…

High Energy Physics - Phenomenology · Physics 2019-09-04 Matteo Becchetti , Roberto Bonciani , Valerio Casconi , Andrea Ferroglia , Simone Lavacca , Andreas von Manteuffel

We present the analytic computation of the master integrals associated to certain two-loop non-planar topologies, which are needed to complete the evaluation of the last two color coefficients for the top-pair production in the…

High Energy Physics - Phenomenology · Physics 2019-12-13 Matteo Becchetti , Roberto Bonciani , Valerio Casconi , Andrea Ferroglia , Simone Lavacca , Andreas von Manteuffel

We compute the leading mass corrections to the high-energy behavior of the massive quark vector form factor to three loops in QCD in the double-logarithmic approximation.

High Energy Physics - Phenomenology · Physics 2017-06-28 Tao Liu , Alexander A. Penin , Nikolai Zerf

We present the analytic expressions for the two-loop form factors for the production or decay of pseudo-scalar quarkonia, in a scheme where the quarks are produced at threshold. We consider the two-loop amplitude for the process $\gamma…

High Energy Physics - Phenomenology · Physics 2023-03-22 Samuel Abreu , Matteo Becchetti , Claude Duhr , Melih A. Ozcelik

We present numerical results for the two-loop virtual amplitude entering the NNLO corrections to Higgs boson production in association with a top quark pair at the LHC, focusing, as a proof of concept of our method, on the part of the…

High Energy Physics - Phenomenology · Physics 2024-05-31 Bakul Agarwal , Gudrun Heinrich , Stephen P. Jones , Matthias Kerner , Sven Yannick Klein , Jannis Lang , Vitaly Magerya , Anton Olsson

In this contribution we provide further details to the recent calculation of QCD corrections to massive three-loop form factors presented in Ref. [1].

High Energy Physics - Phenomenology · Physics 2018-07-26 Roman N. Lee , Alexander V. Smirnov , Vladimir A. Smirnov , Matthias Steinhauser

We review the electromagnetic form factor of heavy quarks with emphasis on the QCD radiative corrections at two-loop order in the perturbative expansion. We discuss important properties of the heavy-quark form factor such as its…

High Energy Physics - Phenomenology · Physics 2010-05-12 S. Moch

We compute the three-loop QCD corrections to the massive quark-anti-quark-photon form factors $F_1$ and $F_2$ involving a closed loop of massless fermions. This subset is gauge invariant and contains both planar and non-planar…

High Energy Physics - Phenomenology · Physics 2018-04-18 Roman N. Lee , Alexander V. Smirnov , Vladimir A. Smirnov , Matthias Steinhauser
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