On the factorization of chiral logarithms in the pion form factors

• Published in: The journal of high energy physics Vol. 2012; no. 9
• Main Authors: Colangelo, G., Procura, M., Rothen, L., Stucki, R., Castellà, J. Tarrús
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01-09-2012; Springer Nature B.V
• Subjects: Chiral dynamics; Classical and Quantum Gravitation; Elementary Particles; Factorization; Form factors; High energy physics; Logarithms; Perturbation theory; Physics; Physics and Astronomy; Pions; Quantum Field Theories; Quantum Field Theory; Quantum Physics; Relativity Theory; String Theory; Chiral Lagrangians; QCD
• ISSN: 1029-8479; 1029-8479
• DOI: 10.1007/JHEP09(2012)081

A
bstract
The recently proposed hard-pion chiral perturbation theory predicts that the leading chiral logarithms factorize with respect to the energy dependence in the chiral limit. This claim has been successfully tested in the pion form factors up to two loops in chiral perturbation theory. In the present paper we explain this factorization property at two loops and even show that it is valid to all orders for a subclass of diagrams. We also demonstrate that factorization is violated starting at three loops.