Hadronic Calorimeter Cosmic Muon Calibrations

The sPHENIX experiment has two layers of the Hadronic Calorimeter (HCal). The outer HCal is the outermost layer outside the solenoid coil, while the inner HCal is inside the magnet immediately outside the Electromagnetic Calorimeter. The sPHENIX program calls for precise measurements of jets to analyze the microscopic properties of the strongly interacting quark-gluon plasma and therefore requires a well-calibrated energy scale for the calorimeters. This talk will focus on the progress of the calibration for both the inner and outer HCal using cosmic muons. We record the energy deposited by muons passing through the sectors, and select events where the muons pass through all tiles in a tower. Our primary diagnostic is the Most Probable Value (MPV) of the ADC distributions for such events. The MPV's are then subjected to corrections for the temperatures and the pre-determined Performance Ratio (PR) of the individual tiles in each tower. The corrected MPV's determine the gain of each tower. We will use these data to calibrate the response and to ensure the uniform performance of the towers.