Anomalous Ward identities for on-shell amplitudes at the conformal fixed point

Abstract Conformal symmetry underlies many massless quantum field theories, but little is known about the consequences of this powerful symmetry for on-shell scattering amplitudes. Working in a dimensionally-regularised ϕ 3 model at the conformal fixed point, we show that the on-shell renormalised a...

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Main Authors: Dmitry Chicherin, Johannes Henn, Simone Zoia
Format: Article
Language:English
Published: SpringerOpen 2023-06-01
Series:Journal of High Energy Physics
Subjects:
Online Access:https://doi.org/10.1007/JHEP06(2023)110
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author Dmitry Chicherin
Johannes Henn
Simone Zoia
author_facet Dmitry Chicherin
Johannes Henn
Simone Zoia
author_sort Dmitry Chicherin
collection DOAJ
description Abstract Conformal symmetry underlies many massless quantum field theories, but little is known about the consequences of this powerful symmetry for on-shell scattering amplitudes. Working in a dimensionally-regularised ϕ 3 model at the conformal fixed point, we show that the on-shell renormalised amplitudes satisfy anomalous conformal Ward identities. Each external on-shell state contributes two terms to the anomaly. The first term is proportional to the elementary field anomalous dimension, and thus involves only lower-loop information. We show that the second term can be given as the convolution of a universal collinear function and lower-order amplitudes. The computation of the conformal anomaly is therefore simpler than that of the amplitude at the same perturbative order, which gives our anomalous conformal Ward identities a strong predictive power in perturbation theory. Finally, we show that our result is also of practical importance for dimensionally-regularised amplitudes away from the conformal fixed point.
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spelling doaj.art-4ef12dc6088f4ad8a11e85af79e8e2382023-09-24T11:05:21ZengSpringerOpenJournal of High Energy Physics1029-84792023-06-012023615710.1007/JHEP06(2023)110Anomalous Ward identities for on-shell amplitudes at the conformal fixed pointDmitry Chicherin0Johannes Henn1Simone Zoia2LAPTh, Université Savoie Mont Blanc, CNRSMax-Planck-Institut für Physik, Werner-Heisenberg-InstitutDipartimento di Fisica and Arnold-Regge Center, Università di Torino, and INFN, Sezione di TorinoAbstract Conformal symmetry underlies many massless quantum field theories, but little is known about the consequences of this powerful symmetry for on-shell scattering amplitudes. Working in a dimensionally-regularised ϕ 3 model at the conformal fixed point, we show that the on-shell renormalised amplitudes satisfy anomalous conformal Ward identities. Each external on-shell state contributes two terms to the anomaly. The first term is proportional to the elementary field anomalous dimension, and thus involves only lower-loop information. We show that the second term can be given as the convolution of a universal collinear function and lower-order amplitudes. The computation of the conformal anomaly is therefore simpler than that of the amplitude at the same perturbative order, which gives our anomalous conformal Ward identities a strong predictive power in perturbation theory. Finally, we show that our result is also of practical importance for dimensionally-regularised amplitudes away from the conformal fixed point.https://doi.org/10.1007/JHEP06(2023)110Scale and Conformal SymmetriesScattering Amplitudes
spellingShingle Dmitry Chicherin
Johannes Henn
Simone Zoia
Anomalous Ward identities for on-shell amplitudes at the conformal fixed point
Journal of High Energy Physics
Scale and Conformal Symmetries
Scattering Amplitudes
title Anomalous Ward identities for on-shell amplitudes at the conformal fixed point
title_full Anomalous Ward identities for on-shell amplitudes at the conformal fixed point
title_fullStr Anomalous Ward identities for on-shell amplitudes at the conformal fixed point
title_full_unstemmed Anomalous Ward identities for on-shell amplitudes at the conformal fixed point
title_short Anomalous Ward identities for on-shell amplitudes at the conformal fixed point
title_sort anomalous ward identities for on shell amplitudes at the conformal fixed point
topic Scale and Conformal Symmetries
Scattering Amplitudes
url https://doi.org/10.1007/JHEP06(2023)110
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