Analysis strategies for the updated geoneutrino measurement with Borexino

Borexino is a 280-ton liquid scintillator detector located at the Laboratori Nazionali del Gran Sasso (LNGS), Italy and is one of the two detectors that has measured geoneutrinos so far. The unprecedented radio-purity of the scintillator, the shielding with highly purified water, and the placement of the detector at a 3800 m w.e. depth have resulted in very low background levels and have made Borexino an excellent apparatus for geoneutrino measurements. The analysis techniques of the latest geoneutrino results with Borexino were presented using the data obtained from December 2007 to April 2019, corresponding to an exposure of (1.12 ± 0.05) ×1032 protons × yr. Enhanced analysis techniques, such as an increased fiducial volume, improved veto for cosmogenic backgrounds, extended energy and coincidence time windows, as well as a more efficient α/β particle discrimination have been adopted in this measurement. The updated statistics and these elaborate resulted in a geoneutrino signal of 47.0+8.4−7.7 (stat)+2.4−1.9 (sys) TNU with +18.3−17.2% total precision.