QED radiative corrections to the decay π0→e+e-

Abstract

We reconsider QED radiative corrections (RC) to the π 0 → e + e − decay width. One kind of RC investigated earlier has a renormalization group origin and can be associated with the final state interaction of electron and positron. It determines the distribution of lepton pair invariant masses in the whole kinematic region. The other type of RC has a double-logarithmic character and is related to almost on-mass-shell behavior of the lepton form factors. The total effect of RC for the π 0 → e + e − decay is estimated to be 3.2% and for the decay η → e + e − is 4.3%.

Electromagnetic transition form factor and radiative corrections in decays of neutral pions

“…which differs significantly from previous approximate calculations done in [5] and [6], where for δ(0.95) the authors obtained -13.8 % and -13.3 %, respectively. After taking into account a proper calculation of the radiative corrections in the QED sector, the original discrepancy between SM and KTeV experiment reduces to the 2 σ level or less.…”

Decays of neutral pions: Electromagnetic transition form factor and radiative corrections

“…which differs significantly from the previous approximate calculations done in [7] and [8], where for δ(0.95) the authors obtained -13.8 % and -13.3 %, respectively. Due to its weak dependence on χ (r) it can be considered model-independent.…”

Chiral expansions of pi0 decays

“…However, setting the limits on this vertex by calculating radiative corrections is of great importance. A new calculation in this direction [33] shows that the radiative corrections used in the extrapolation are indeed under control. This calculation together with the correct description of the Dalitz decay (which was used in normalization in order to improve systematic error) is under investigation [34].…”