The XIX International Conference on Topics in Astroparticle and Underground Physics (TAUP2025)

Search for double electron capture in Sn-112 using gamma-ray TES

27 Aug 2025, 16:40

20m

North Hall #2

Oral Neutrino Physics and Astrophysics Neutrino Physics and Astrophysics

Speaker

Atsuto Takeuchi (RCNS, Tohoku University)

Description

Double electron capture (ECEC) is a second-order weak interaction
process in which two orbital electrons are captured simultaneously by a
nucleus. Its half-life serves as a sensitive probe for testing nuclear
structure models. To date, only ECEC in xenon-124 has been observed,
indicating the need for new experimental techniques. In this
presentation, we report a search for double electron capture in Sn-112
using transition edge sensors (TES). The use of gamma-ray TES with Sn
absorber allows us to search for ECEC reaction efficiently by detecting
X-rays and/or Auger electrons following ECEC. We will present the
current status of the measurement using 8-pixels TESs array with 0.8 mm
cubic tin absorbers, and will discuss the future sensitivity assuming
the increase of pixelization and fiducial volume.