Theoretical progress on pi pi scattering lengths and phases

Abstract

pi pi scattering at low energy is sensitive to the structure of the QCD vacuum. I review the calculations of the pi pi scattering lengths and phases, and group them in three cathegories: 1. those based on very general theoretical constraints (like dispersion relations and crossing symmetry) and phenomenology, 2. those which in addition make explicit use of chiral symmetry, 3. the first-principle ones, done with lattice QCD. I then compare these to the experimental results. Thanks to recent progress in all these and in the experimental determination of the scattering lengths we are improving substantially our knowledge of the QCD vacuum.

11 pages, talk given at the KAON International Conference, May 21-25 2007 Laboratori Nazionali di Frascati dell'INFN, Rome, Italy

References in corpus (14)

• Light pseudoscalar decay constants, quark masses, and low energy constants from three-flavor lattice QCD
• Resonances in $J/\psi \to \varphi {\pi }^{+}{\pi }^{-}$ and $\varphi K^{+}{K}^{-}$
• Dynamical Twisted Mass Fermions with Light Quarks
• The pion-pion scattering amplitude
• I=2 pi-pi Scattering from Fully-Dynamical Mixed-Action Lattice QCD
• Precise Determination of the I=2 pipi Scattering Length from Mixed-Action Lattice QCD
• Experimental status of the $\pi \pi$ isoscalar S wave at low energy: $f_0(600)$ pole and scattering length
• Elimination of ambiguities in pion-pion phase shifts using crossing symmetry
• pi pi scattering
• Location, correlation, radiation: where is the $\sigma$, what is its structure and what is its coupling to photons?
• On the precision of chiral-dispersive calculations of $\pi \pi$ scattering
• Reconclining phi radiative decays with other data for a0(980), fo(980), pi-pi -> KK and pi-pi -> eta-eta
• Theoretical progress on cusp effect and Kl4 decays
• Low energy constants from the MILC Collaboration

Cited by in corpus (6)

• Regge analysis of the pi pi scattering amplitude
• Isospin breaking in Kl4 decays
• Model independent determination of the sigma pole
• Theoretical progress on cusp effect and Kl4 decays
• The electromagnetic effects in $K_{e4}$ decay
• New results on kaon decays from NA48/2