Corrections Beyond the Leading Order in pi(0) -> e(+)e(-) Process

Abstrakt

We briefly summarize experimental and theoretical results on the rare decay pi(0) -> e(+)e(-). Two-loop QED corrections are reviewed and the bremsstrahlung contribution beyond the soft-photon approximation is analytically calculated.

Using the leading logarithm approximation, the possible contribution of QCD corrections is estimated. The complete result can be used to fit the value of the contact interaction coupling chi((r)) to the recent KTeV experiment, with the result chi((r))(M-rho) 4.5 +/- 1.0.

Klíčová slova

• Decays of pi mesons
• Chiral Lagrangians
• Electromagnetic corrections to strong
• and weak-interaction processes