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Higher-order tree-level amplitudes in the nonlinear sigma model

Bijnens, Johan LU orcid ; Kampf, Karol LU and Sjö, Mattias LU (2019) In Journal of High Energy Physics 2019(11).
Abstract

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... (More)

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.

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author
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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Chiral Lagrangians, Effective Field Theories, Scattering Amplitudes, Spon- taneous Symmetry Breaking
in
Journal of High Energy Physics
volume
2019
issue
11
article number
74
publisher
Springer
external identifiers
  • scopus:85075196432
ISSN
1029-8479
DOI
10.1007/JHEP11(2019)074
language
English
LU publication?
yes
id
874c90dd-4eb9-4836-9e15-440006b88d8f
date added to LUP
2019-12-06 11:02:44
date last changed
2024-04-17 00:46:49
@article{874c90dd-4eb9-4836-9e15-440006b88d8f,
  abstract     = {{<p>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(p<sup>2</sup>), to 6 legs at next-to- next-to-next-to-leading order, O(p<sup>8</sup>). 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.</p>}},
  author       = {{Bijnens, Johan and Kampf, Karol and Sjö, Mattias}},
  issn         = {{1029-8479}},
  keywords     = {{Chiral Lagrangians; Effective Field Theories; Scattering Amplitudes; Spon- taneous Symmetry Breaking}},
  language     = {{eng}},
  number       = {{11}},
  publisher    = {{Springer}},
  series       = {{Journal of High Energy Physics}},
  title        = {{Higher-order tree-level amplitudes in the nonlinear sigma model}},
  url          = {{http://dx.doi.org/10.1007/JHEP11(2019)074}},
  doi          = {{10.1007/JHEP11(2019)074}},
  volume       = {{2019}},
  year         = {{2019}},
}