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Photo of Johan Bijnens

Johan Bijnens

Professor

Photo of Johan Bijnens

An analytic analysis of the pion decay constant in three-flavoured chiral perturbation theory

Author

  • B. Ananthanarayan
  • Johan Bijnens
  • Shayan Ghosh

Summary, in English

A representation of the two-loop contribution to the pion decay constant in SU(3) chiral perturbation theory is presented. The result is analytic up to the contribution of the three (different) mass sunset integrals, for which an expansion in their external momentum has been taken. We also give an analytic expression for the two-loop contribution to the pion mass based on a renormalized representation and in terms of the physical eta mass. We find an expansion of Fπ and Mπ2 in the strange-quark mass in the isospin limit, and we perform the matching of the chiral SU(2) and SU(3) low-energy constants. A numerical analysis demonstrates the high accuracy of our representation, and the strong dependence of the pion decay constant upon the values of the low-energy constants, especially in the chiral limit. Finally, we present a simplified representation that is particularly suitable for fitting with available lattice data.

Department/s

  • Theoretical Particle Physics

Publishing year

2017-07-01

Language

English

Publication/Series

European Physical Journal C

Volume

77

Issue

7

Document type

Journal article

Publisher

Springer

Topic

  • Subatomic Physics

Status

Published

ISBN/ISSN/Other

  • ISSN: 1434-6044