On the Lifetime of the pi+pi- Atom
High Energy Physics - Phenomenology
2009-10-31 v1
Abstract
The pi+pi- atom decays -in the ground state - predominantly into two neutral pions. We present a general expression for the corresponding decay width in the framework of QCD (including photons). It contains all terms at leading and next-to-leading order in isospin breaking. The result allows one to evaluate the combination |a_0-a_2| of pi-pi S-wave scattering lengths from pi+pi- lifetime measurements, like the one presently performed by the DIRAC experiment at CERN.
Cite
@article{arxiv.hep-ph/9905309,
title = {On the Lifetime of the pi+pi- Atom},
author = {A. Gall and J. Gasser and V. E. Lyubovitskij and A. Rusetsky},
journal= {arXiv preprint arXiv:hep-ph/9905309},
year = {2009}
}
Comments
4 pages, LaTeX-file