Ponente
Descripción
Dark matter searches using dual-phase xenon time projection chambers (LXe-TPC), such as LUX-ZEPLIN (LZ), use the ratio of charge signal to light signal to discriminate between electron recoils and nuclear recoils. The charge and light yields of electron recoils are often calibrated with 𝛽-decays, such as 3H and 212Pb. These 𝛽-decays produce recoils primarily from outer shell electrons, while other processes may result in vacancies in inner electron shells. In all cases, contributions from the subsequent atomic de-excitation must be calibrated. Previously, the XELDA LXe-TPC has measured the charge and light yields of these atomic de-excitations, using 127Xe electron capture (EC) decays. This result showed that the yields from atomic de-excitations following inner-shell electron captures differed from those of 𝛽-decays, appearing somewhat more ‘nuclear-recoil like’. Here, I calibrate this effect using in-situ data from LZ, demonstrating potential for in-situ calibrations from future large LXe-TPCs. With these inner shell atomic de-excitation calibrations, we can better-inform our modelling of not only 127Xe EC decays, but also neutrino - inner shell electron scatters and 124Xe ECEC decays, reducing risk of false discovery claims.
