A full Monte Carlo simulation for keV-sterile neutrino searches with the KATRIN experiment

Sterile neutrinos are predicted by several extensions to the Standard Model and, if their mass falls within the keV range, they present a compelling dark matter candidate. One potential searching method involves looking for a kink-like distortion in the β spectrum. The Karlsruhe Tritium Neutrino Experiment (KATRIN) uses a tritium source to measure the neutrino effective mass, focusing on the endpoint where the mass effect is the clearest

The next phase of the KATRIN experiment, known as TRISTAN, seeks to extend this search across the entire tritium spectrum. This phase requires the installation of a new multi-pixel silicon drift detector and a specialized readout system, as well as significant modifications to the KATRIN beamline to improve sensitivity.

In this phase, sensitivity to keV sterile neutrinos is strongly influenced by systematic effects, including electron scattering in the source, detector response, and other factors. Addressing these challenges requires a highly efficient Monte Carlo (MC) simulation of the entire KATRIN beamline, capable of generating high-statistics datasets.

In this presentation, we introduce the KATRIN full MC simulation developed using Geant4. ... mehrWe will outline its key components, assess its performance, and present preliminary studies of systematic uncertainties affecting the search for keV-scale sterile neutrinos.