Speaker
Description
Precise and stable energy calibration of hadronic calorimeters is essential for reliable jet and energy measurements in high-energy nuclear collisions. In the sPHENIX experiment, the hadronic calorimeter (HCAL) consists of an inner (IHCal) and an outer (OHCal) section, composed of scintillating tiles interleaved with absorber plates and read out via wavelengthshifting fibers coupled to silicon photomultipliers (SiPMs), whose response varies with operating conditions such as temperature. Continuous calibration and performance monitoring are therefore required to ensure detector stability.
In this poster, we present calibration studies of the sPHENIX HCAL using cosmic-ray muons and LED-based monitoring data. Cosmic-ray muons provide a clean source of minimum-ionizing particles in the absence of beam collisions and are used to study channel-to-channel response uniformity and signal stability. Because cosmic-ray muons traverse the full calorimeter and deposit clean minimum-ionizing signals, these measurements are well suited for studying response uniformity in both IHCal and OHCal.
In parallel, LED calibration data are used to investigate the temperature dependence of the SiPM response in both IHCal and OHCal. Signal amplitudes are extracted using waveform template fitting and correlated with measured temperatures to determine tower-by-tower correction factors. A clear linear dependence of the response on temperature is observed, and applying these corrections significantly reduces time-dependent gain variations.
The combined use of cosmic-ray and LED calibration techniques provides a robust and complementary approach for monitoring HCAL performance, ensuring a stable energy scale and reduced systematic uncertainties for sPHENIX physics analyses.
| Is this an experimental talk? | Yes |
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| Is this on behalf of a collaboration? | Yes |
| Which collaboration? | sPHENIX |
| Are you willing to present as a poster if it is not selected for oral presentation? | Yes |