Fig. 4: Methodology for 40K geoneutrino signal extraction.
From: Probing Earth’s missing potassium using the antimatter signature of geoneutrinos
Reactor antineutrinos as well as 238U and 232Th geoneutrino fluxes are determined with small uncertainty by high-statistics measurements of Inverse Beta Decay or IBD(p) events from which their contribution to IBD(63Cu) events can be inferred at the percent-level. Those same antineutrino contributions need to be subtracted over the [1.189, 1.311] MeV geoneutrino energy range, as they are effectively an irreducible background to the IBD(63Cu) based 40K geoneutrino signal. The histograms are illustrative; their amplitudes are not to scale, and the error bars qualitatively represent the expected statistical uncertainty for each component, highlighting the contrast between the well-measured IBD(p) signal components and the low-statistics IBD(63Cu) signal.
