Modern Analytic Techniques for Perturbative Amplitude Calculations in Yang-Mills and Gravity

Lead Research Organisation: Swansea University
Department Name: College of Science

Abstract

We will use modern analytic techniques in order to determine perturbative amplitudes in Yang-Mills and gravity.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
ST/S505778/1 01/10/2018 30/09/2022
2280788 Studentship ST/S505778/1 01/10/2019 31/03/2023 Adam Dalgleish
ST/T506473/1 01/10/2019 30/09/2023
2280788 Studentship ST/T506473/1 01/10/2019 31/03/2023 Adam Dalgleish
ST/V507143/1 01/10/2020 30/09/2024
2280788 Studentship ST/V507143/1 01/10/2019 31/03/2023 Adam Dalgleish
 
Description A number of new quantum amplitudes (related to the likelihood of gluon scattering) were calculated in an analytic form.

Specifically, interactions of gluons in pure Yang-Mills theory were considered, for the case where all gluons have positive helicity. Previous work often separates these amplitudes into "partial amplitudes" each related to a different colour charge structure. Various partial amplitudes are known up to a complexity of two loops in the interaction, for example the "leading in colour" partial amplitude for six-gluon two-loop interactions was published shortly before this work began.

Using the methods of unitarity and augmented recursion, the full-colour (all partial amplitudes) forms were calculated for six-gluon and seven-gluon amplitudes. These results show interesting symmetries in their analytic forms, which may allow future work to propose more general expressions for scattering amplitudes.

As part of the work, the augmented recursion method was also refined.
Exploitation Route The amplitudes calculated are useful for researchers carrying out tests of the Standard Model of particle physics, particularly at the high-precision area currently being approached. Results at particle colliders (such as the LHC) provide experimental data that must be compared against theoretical scattering predictions such as these, in order to test our theories.

Other researchers in theoretical particle physics may wish to continue calculating amplitudes of greater complexity (more gluons, more loops, different helicity configurations) with the results of this work a guide. Refinements to the augmented recursion process suggested in this work improve its utility to those researchers.
Sectors Education,Other