Anticipating antineutrinos at the Theia detector*

Theia is a proposed large-scale novel neutrino detector designed to discriminate between Cherenkov and scintillation signals and enable a broad physics program. The baseline design consists of a tank filled with water-based liquid scintillator (WbLS), a novel target which would combine reconstruction of particle direction from the Cherenkov signal, with the excellent energy resolution and low threshold of a scintillator detector. This talk will focus on the sensitivity towards the detection of low-energy antineutrinos in the context of the 25-ktonne Theia detector at Sanford Underground Research Facility (SURF). Currently, only two detectors in the world have measured geoneutrinos, antineutrinos originating from the radioactive decays of long-lived isotopes naturally present in the crust and mantle. It is critical to gather geoneutrino data from more detectors at various locations around the world as it can vary drastically. We demonstrate Theia's sensitivity to measure the antineutrino fluxes via Inverse-Beta Decay (IBD) interactions and collect an unprecedented amount of geoneutrino data in only one year to extract the crust/mantle contribution.