Johan Bijnens
Professor, Deputy Head of Division
Higher-order tree-level amplitudes in the nonlinear sigma model
Author
Summary, in English
We present a generalisation of the flavour-ordering method applied to the chiral nonlinear sigma model with any number of flavours. We use an extended Lagrangian with terms containing any number of derivatives, organised in a power-counting hierarchy. The method allows diagrammatic computations at tree-level with any number of legs at any order in the power-counting. Using an automated implementation of the method, we calculate amplitudes ranging from 12 legs at leading order, O(p2), to 6 legs at next-to- next-to-next-to-leading order, O(p8). In addition to this, we generalise several properties of amplitudes in the nonlinear sigma model to higher orders. These include the double soft limit and the uniqueness of stripped amplitudes.
Department/s
- Theoretical Particle Physics - Has been reorganised
Publishing year
2019
Language
English
Publication/Series
Journal of High Energy Physics
Volume
2019
Issue
11
Document type
Journal article
Publisher
Springer
Topic
- Subatomic Physics
Keywords
- Chiral Lagrangians
- Effective Field Theories
- Scattering Amplitudes
- Spon- taneous Symmetry Breaking
Status
Published
ISBN/ISSN/Other
- ISSN: 1029-8479