Temperature Dependence of SiPM Response in sPHENIX HCal: LED Runs and GSU Test Stand Studies

We investigate the temperature dependence of Silicon Photomultiplier (SiPM) responses within the sPHENIX Hadronic Calorimeter (HCal), using data from both sPHENIX LED runs and a cosmic ray test stand at Georgia State University (GSU). The analysis examines the correlation between the ADC Most Probable Value (MPV) and temperature for the Outer and Inner HCal. Results from LED runs conducted between April and June 2024 indicate temperature correction factors ranging from approximately 3% to 7% for OHCal towers, with a broader distribution observed in the IHCal. Consistent findings from the GSU test stand show a correction factor of approximately 5%, corroborating the sPHENIX LED findings. The talk identifies sector- and tower-level variations and discusses their implications for the energy calibration of the calorimeter system. These results highlight the importance of temperature-dependent corrections for accurate SiPM-based calorimeter performance, informing future calibration strategies.