Calibration of the Gerda experiment.

Area of Science:

• Nuclear Physics
• Particle Physics
• Experimental Physics

Background:

• Neutrinoless double-beta decay is a hypothetical process not predicted by the Standard Model.
• Observing this decay would provide insights into neutrino properties and fundamental physics.
• High-purity germanium detectors are sensitive tools for searching for rare nuclear events.

Purpose of the Study:

• To detail the calibration process for the GERmanium Detector Array (Gerda) experiment.
• To describe the data analysis methods used to ensure energy reconstruction and resolution.
• To preserve the excellent resolution of germanium detectors over several years of data collection.

Main Methods:

• Utilizing an array of approximately 40 high-purity, isotopically enriched germanium detectors.
• Employing regular Thorium-228 (Th) calibrations to monitor energy resolution and stability.
• Developing data analysis techniques to combine measurements from multiple detectors over extended periods.

Main Results:

• Established a robust calibration procedure for the Gerda germanium detectors.
• Quantified the energy resolution and stability of the detectors over the experiment's duration.
• Demonstrated methods to maintain detector performance for rare event searches.

Conclusions:

• The Gerda experiment's calibration and analysis framework is essential for sensitive searches for neutrinoless double-beta decay.
• Precise energy measurements are critical for background discrimination in rare event searches.
• The described methods ensure the integrity of data for future analyses.