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

This paper describes a method for energy calibration of laterally segmented electromagnetic calorimeters based on the detection of two-photon decays of π⁰ mesons. The calibration procedure performs a χ² function minimization between the measured π⁰ energy in the calorimeter and its expected energy deduced from the π⁰ 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 π⁰ is detected. This technique is applied to monitor daily the calibration coefficients of the calorimeter used in the Jefferson Lab Hall A DVCS experiments. (authors)