The Off Shell $Ï$-$Ï$ Mixing in the QCD Sum Rules
arXiv:nucl-th/9304021 · doi:10.1103/PhysRevC.49.452
Abstract
The $q^2$ dependence of the $Ï-Ï$ mixing amplitude is analyzed with the use of the QCD sum rules and the dispersion relation. Going off shell the mixing decreases, changes sign at $q^2 \simeq 0.4 m_Ï^2 > 0$ and is negative in the space like region. Implications of this result to the isospin breaking part of the nuclear force are discussed.
26 pages + 11 figures (PostScript)