Muons in the Calorimeters: Energy Loss Corrections and Muon Tagging

The muon spectrometer is the outermost subdetector of the ATLAS detector, beginning after a muon has traversed 100 radiation lengths of material. Muon momentum measurements must be corrected for energy loss in the calorimeters and the inert material before the muons reach the muon spectrometer. Energy lost in the calorimeters can be estimated from parameterizations or from a measurement of the energy deposited in the calorimeters. In addition, the muon energy loss measurement can be used to tag muons not reconstructed in the muon spectrometer due to inefficiencies, spectrometer acceptance or their low momenta. In this document we discuss different algorithms developed to perform the energy loss correction in the muon reconstruction. We compare the performance of the muon reconstruction algorithms before and after the energy loss correction is applied. In addition, we describe the muon tagging algorithms, based on measurements obtained in the calorimeters, and contrast their performance in different simulated data samples.