Speaker
Description
XENONnT provides a unique low-energy electron-recoil (LowER) channel, enabling sensitivity to sub-MeV solar neutrinos and neutrino–electron interactions at low momentum transfer. The LowER channel operates with an ultra-low electron-recoil background at the level of O(10) events/(t·y·keV) and benefits from precise efficiency modeling at low energies. A central challenge for a solar pp neutrino measurement in XENONnT is the control of low-energy backgrounds, dominated by Pb214 from the Rn222 decay chain. Dedicated radon calibration campaigns in Science Run 1 were performed to characterize and constrain this background. This poster presents the physics motivation of solar pp neutrinos in the LowER channel, along with the background model, calibration strategy, and analysis framework developed within XENONnT.