One-loop amplitudes for $t\bar{t}j$ and $t\bar{t}\gamma$ productions at the LHC through $\mathcal{O}(\epsilon^2)$, by Souvik Bera, Colomba Brancaccio, Dhimiter Canko, Heribertus Bayu Hartanto

SciPost Physics Home Authoring Refereeing Submit a manuscript About One-loop amplitudes for $t\bar{t}j$ and $t\bar{t}\gamma$ productions at the LHC through $\mathcal{O}(\epsilon^2)$ Souvik Bera, Colomba Brancaccio, Dhimiter Canko, Heribertus Bayu Hartanto SciPost Phys. 19, 165 (2025) · published 24 December 2025 doi: 10.21468/SciPostPhys.19.6.165 pdf BiBTeX RIS Submissions/Reports Abstract We present analytic expressions for the one-loop QCD helicity amplitudes contributing to top-quark pair production in association with a photon or a jet at the Large Hadron Collider (LHC), evaluated through $\mathcal{O}(\epsilon^2)$ in the dimensional regularisation parameter, $\epsilon$. These amplitudes are required to construct the two-loop hard functions that enter the NNLO QCD computation. The helicity amplitudes are expressed as linear combinations of algebraically independent components of the $\epsilon$-expanded master integrals, with the corresponding rational coefficients written in terms of momentum-twistor variables. We derive differential equations for the pentagon functions, which enable efficient numerical evaluation via generalised power series expansion method. × TY - JOURPB - SciPost FoundationDO - 10.21468/SciPostPhys.19.6.165TI - One-loop amplitudes for $t\bar{t}j$ and $t\bar{t}\gamma$ productions at the LHC through $\mathcal{O}(\epsilon^2)$PY - 2025/12/24UR - https://scipost.org/SciPostPhys.19.6.165JF - SciPost PhysicsJA - SciPost Phys.VL - 19IS - 6SP - 165A1 - Bera, SouvikAU - Brancaccio, ColombaAU - Canko, DhimiterAU - Hartanto, Heribertus BayuAB - We present analytic expressions for the one-loop QCD helicity amplitudes contributing to top-quark pair production in association with a photon or a jet at the Large Hadron Collider (LHC), evaluated through $\mathcal{O}(\epsilon^2)$ in the dimensional regularisation parameter, $\epsilon$. These amplitudes are required to construct the two-loop hard functions that enter the NNLO QCD computation. The helicity amplitudes are expressed as linear combinations of algebraically independent components of the $\epsilon$-expanded master integrals, with the corresponding rational coefficients written in terms of momentum-twistor variables. We derive differential equations for the pentagon functions, which enable efficient numerical evaluation via generalised power series expansion method.ER - × @Article{10.21468/SciPostPhys.19.6.165, title={{One-loop amplitudes for $t\bar{t}j$ and $t\bar{t}\gamma$ productions at the LHC through $\mathcal{O}(\epsilon^2)$}}, author={Souvik Bera and Colomba Brancaccio and Dhimiter Canko and Heribertus Bayu Hartanto}, journal={SciPost Phys.}, volume={19}, pages={165}, year={2025}, publisher={SciPost}, doi={10.21468/SciPostPhys.19.6.165}, url={https://scipost.org/10.21468/SciPostPhys.19.6.165},} Supplementary Information External links to supplemental resources; opens in a new tab. Code repository Data repository Ontology / Topics See full Ontology or Topics database. Quantum chromodynamics (QCD) perturbation theory Authors / Affiliations: mappings to Contributors and Organizations See all Organizations. 1 Souvik Bera, 2 3 4 Colomba Brancaccio, 5 6 Dhimiter Canko, 1 7 Heribertus Bayu Hartanto 1 Asia Pacific Center for Theoretical Physics [APCTP] 2 Università degli Studi di Torino / University of Turin [UNITO] 3 Istituto Nazionale di Fisica Nucleare Sezione di Torino / INFN Sezione di Torino 4 Arnold Regge Center 5 Università di Bologna / University of Bologna [UNIBO] 6 INFN Sezione di Bologna / INFN Bologna [INFN Bologna] 7 포항공과대학교 / Pohang University of Science and Technology [POSTECH] Funders for the research work leading to this publication Asia Pacific Center for Theoretical Physics [APCTP] European Research Council [ERC] Ministero dell’Istruzione, dell’Università e della Ricerca (MIUR) (through Organization: Ministero dell'Istruzione, dell'Università e della Ricerca / Ministry of Education, Universities and Research [MIUR])