Rare decay pi(0) -> e(+)e(-): on corrections beyond the leading order

Abstrakt

The preceding experimental and theoretical results on the rare decay pi(0) -> e(+)e(-) are briefly summarized. Already computed two-loop QED corrections are reviewed and the bremsstrahlung contribution beyond the soft-photon approximation is analytically calculated.

The possible further contribution of QCD loop corrections is estimated using the leading logarithm approximation. 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

• chiral perturbation-theory
• radiative-corrections
• form-factors
• qcd