Reconstruction of Cosmic Muon Tracks Inside the Half-Sector of the ECal MPD/NICA Electromagnetic Calorimeter to Align the Tower Responses

The electromagnetic calorimeter (ECal) of the multipurpose detector (MPD)/NICA is a modular cylindrical system consisting of 50 half-sectors and containing 38 400 towers of the “shashlik” type. The main task of ECal is to measure the energies and positions of the hits of photons and electrons. To do this, it is necessary to align the tower responses and energy calibration. Preliminary alignment can be obtained using cosmic muons that cross the volume of the electromagnetic calorimeter. In this paper, we discuss an algorithm for reconstructing muon tracks based on the iterative Hough transform and an algorithm for correcting tracks based on the dependence of the released energy on the path length in the tower using the maximum likelihood method.