Search for Dark Photon at NA48/2, and measurement of π0 form factor

The NA48/2 experiment at CERN performed a search for the dark photon (A') via the decay chain pi(0) -> gamma A', A' -> e(+)e(-) . Using a sample of similar to 1.7.10(7) neutral pions tagged from K-+/- -> pi(+/-)pi x(D)(0) and K +/- -> mu(+/-) pi(0)(D)nu decays collected in 2003-04 no signal is observed. The limits in the plane dark photon mixing parameter epsilon(2) versus its mass m(A') are reported. The NA62-RK experiment collected, during the 2007 data taking, a large sample of neutral pion Dalitz decays with a trigger optimised for electrons final states with respect to NA48/2 one. We report the measurement of the pi(0) electromagnetic transition form factor (TFF) slope parameter (a) based on a sample of similar to 1.10(6) pi(0)(D) decays. The preliminary measured value a = (3.70 +/- 0:53(stat) +/- 0.36(syst)).10(2) is compatible with theoretical expectations and previous measurements.