Locally finite two-loop amplitudes for off-shell multi-photon production in electron-positron annihilation
Abstract We study the singularity structure of two-loop QED amplitudes for the production of multiple off-shell photons in massless electron-positron annihilation and develop counterterms that remove their infrared and ultraviolet divergences point by point in the loop integrand. The remainders of t...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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SpringerOpen
2021-04-01
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| Series: | Journal of High Energy Physics |
| Subjects: | |
| Online Access: | https://doi.org/10.1007/JHEP04(2021)222 |
| _version_ | 1818590383422046208 |
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| author | Charalampos Anastasiou Rayan Haindl George Sterman Zhou Yang Mao Zeng |
| author_facet | Charalampos Anastasiou Rayan Haindl George Sterman Zhou Yang Mao Zeng |
| author_sort | Charalampos Anastasiou |
| collection | DOAJ |
| description | Abstract We study the singularity structure of two-loop QED amplitudes for the production of multiple off-shell photons in massless electron-positron annihilation and develop counterterms that remove their infrared and ultraviolet divergences point by point in the loop integrand. The remainders of the subtraction are integrable in four dimensions and can be computed in the future with numerical integration. The counterterms capture the divergences of the amplitudes and factorize in terms of the Born amplitude and the finite remainder of the one-loop amplitude. They consist of simple one- and two-loop integrals with at most three external momenta and can be integrated analytically in a simple manner with established methods. We uncover novel aspects of fully local IR factorization, where vertex and self energy subdiagrams must be modified by new symmetrizations over loop momenta, in order to expose their tree-like tensor structures and hence factorization of IR singularities prior to loop integration. This work is a first step towards isolating locally the hard contributions of generic gauge theory amplitudes and rendering them integrable in exactly four dimensions with numerical methods. |
| first_indexed | 2024-12-16T09:55:40Z |
| format | Article |
| id | doaj.art-f0d30d4b28c04996a79840bc0f2986a4 |
| institution | Directory Open Access Journal |
| issn | 1029-8479 |
| language | English |
| last_indexed | 2024-12-16T09:55:40Z |
| publishDate | 2021-04-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Journal of High Energy Physics |
| spelling | doaj.art-f0d30d4b28c04996a79840bc0f2986a42022-12-21T22:35:56ZengSpringerOpenJournal of High Energy Physics1029-84792021-04-012021418310.1007/JHEP04(2021)222Locally finite two-loop amplitudes for off-shell multi-photon production in electron-positron annihilationCharalampos Anastasiou0Rayan Haindl1George Sterman2Zhou Yang3Mao Zeng4Institute for Theoretical Physics, ETH ZurichInstitute for Theoretical Physics, ETH ZurichC.N. Yang Institute for Theoretical Physics and Department of Physics and Astronomy, Stony Brook UniversityInstitute for Theoretical Physics, ETH ZurichInstitute for Theoretical Physics, ETH ZurichAbstract We study the singularity structure of two-loop QED amplitudes for the production of multiple off-shell photons in massless electron-positron annihilation and develop counterterms that remove their infrared and ultraviolet divergences point by point in the loop integrand. The remainders of the subtraction are integrable in four dimensions and can be computed in the future with numerical integration. The counterterms capture the divergences of the amplitudes and factorize in terms of the Born amplitude and the finite remainder of the one-loop amplitude. They consist of simple one- and two-loop integrals with at most three external momenta and can be integrated analytically in a simple manner with established methods. We uncover novel aspects of fully local IR factorization, where vertex and self energy subdiagrams must be modified by new symmetrizations over loop momenta, in order to expose their tree-like tensor structures and hence factorization of IR singularities prior to loop integration. This work is a first step towards isolating locally the hard contributions of generic gauge theory amplitudes and rendering them integrable in exactly four dimensions with numerical methods.https://doi.org/10.1007/JHEP04(2021)222Perturbative QCDScattering Amplitudes |
| spellingShingle | Charalampos Anastasiou Rayan Haindl George Sterman Zhou Yang Mao Zeng Locally finite two-loop amplitudes for off-shell multi-photon production in electron-positron annihilation Journal of High Energy Physics Perturbative QCD Scattering Amplitudes |
| title | Locally finite two-loop amplitudes for off-shell multi-photon production in electron-positron annihilation |
| title_full | Locally finite two-loop amplitudes for off-shell multi-photon production in electron-positron annihilation |
| title_fullStr | Locally finite two-loop amplitudes for off-shell multi-photon production in electron-positron annihilation |
| title_full_unstemmed | Locally finite two-loop amplitudes for off-shell multi-photon production in electron-positron annihilation |
| title_short | Locally finite two-loop amplitudes for off-shell multi-photon production in electron-positron annihilation |
| title_sort | locally finite two loop amplitudes for off shell multi photon production in electron positron annihilation |
| topic | Perturbative QCD Scattering Amplitudes |
| url | https://doi.org/10.1007/JHEP04(2021)222 |
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