Energy calibration of laterally segmented electromagnetic calorimeters based on neutral pion detection

Abstract

This paper describes a method for energy calibration of laterally segmented electromagnetic calorimeters based on the detection of two-photon decays of $$\pi ^0$$ mesons. The calibration procedure performs a $$\chi ^2$$ function minimization between the measured $$\pi ^0$$ energy in the calorimeter and its expected energy deduced from the $$\pi ^0$$ momentum direction. The performance of this technique is demonstrated with a Monte Carlo simulation of an experimental case where biased calibration coefficients are employed. The real calibration coefficients are restored with less than 1% relative accuracy when a sufficient number of $$\pi ^0$$ is detected. This technique is applied to monitor daily the calibration coefficients of the calorimeter used in the Jefferson Lab Hall A DVCS experiments.