Measurement of the pi^0 -> e^+e^-gamma Dalitz decay at the Mainz Microtron

TL;DR

This paper reports a precise measurement of the pi^0 -> e^+e^-gamma decay at Mainz, determining the transition form factor slope parameter with improved accuracy, consistent with theory and previous experiments.

Contribution

It provides a more precise measurement of the pi^0 electromagnetic transition form factor slope parameter using the Mainz Microtron, enhancing the understanding of pi^0 decay dynamics.

Findings

Measured the slope parameter a_pi = 0.030±0.010

Results agree with existing measurements and theoretical predictions

Achieved lower uncertainty than previous studies

Abstract

The Dalitz decay pi^0 -> e^+e^-gamma has been measured in the gamma p -> pi^0 p reaction with the A2 tagged-photon facility at the Mainz Microtron, MAMI. The value obtained for the slope parameter of the pi^0 electromagnetic transition form factor, a_pi = 0.030+/-0.010_tot, is in agreement with existing measurements of this decay and with recent theoretical calculations. The uncertainty obtained in the value of a_pi is lower than in previous results based on the pi^0 -> e^+e^-gamma decay.