Measurement of the π 0 electromagnetic transition form factor slope

摘要

The NA62 experiment collected a large sample of charged kaon decays in 2007 with a highly efficient trigger for decays into electrons. A measurement of the π 0 electromagnetic transition form factor slope parameter from 1.11 × 10 6 fully reconstructed K ± → π ± π D 0 , π D 0 → e + e ? γ events is reported. The measured value a = ( 3.68 ± 0.57 ) × 10 ? 2 is in good agreement with theoretical expectations and previous measurements, and represents the most precise experimental determination of the slope in the time-like momentum transfer region.