Analysis and interpretation of new low-energy ππ scattering data

2001/12/31 by Sébastien Descotes–Genon, S. Descotes, N. H. Fuchs +2 · 4 citations
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ex #hep-ph

paper · pdf · doi:10.1007/s10052-002-0965-3

published as Eur.Phys.J.C24:469-483,2002 · Published version, to appear in Eur. Phys. J. C

arxiv created 2002/04/15 · openalex publication_date 2002/07/01 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

The recently published E865 data on charged K_e4 decays and Pi-Pi phases are reanalyzed to extract values of the two S-wave scattering lengths, of the subthreshold parameters alpha and beta, of the low-energy constants l3-bar and l4-bar as well as of the main two-flavour order parameters: <u-bar u> and F_pi in the limit m_u = m_d = 0 taken at the physical value of the strange quark mass. Our analysis is exclusively based on direct experimental information on Pi-Pi phases below 800 MeV and on the new solutions of the Roy equations by Ananthanarayan et al. The result is compared with the theoretical prediction relating 2 a₀⁰ - 5 a₀² and the scalar radius of the pion, which was obtained in two-loop Chiral Perturbation Theory. A discrepancy at the 1-sigma level is found and commented upon.

Citations

• Comparison of π K scattering in SU(3) chiral perturbation theory and dispersion relations
• Chiral Symmetry Aspects of the Scalars

Cited by

• On the precision of the theoretical predictions forππscattering
• Sigma pole position and errors of a once and twice subtracted dispersive analysis of pi-pi scattering data
• Resumming QCD vacuum fluctuations in three-flavor Chiral Perturbation Theory
• Isospin breaking in Kℓ4 decay of the neutral kaon