XeSAT2022 - International Workshop on Applications of Noble Gas Xenon to Science and Technology

Neutrinoless double-beta decay search results from KamLAND-Zen with 1 ton-year ^{136}Xe exposure

Non programmé

20m

Main auditorium

0√2β session 1, chair Julien Masbou

Orateur

Hideyoshi Ozaki (Tohoku university)

Description

KamLAND-Zen is a neutrinoless double-beta decay search experiment using a large size liquid scintillator(LS) detector (KamLAND). We started KamLAND-Zen 800 phase with 745 kg of Xenon in 2019.
We achieved to conduct an extremely low radioactive background experiment by reducing the radioactive impurities in the newly fabricated 25-um-thick and 3.8-m-diameter nylon film container for the Xe-loaded LS and developing strong spallation background rejection techniques.
The dominant background after all the analytic background rejection is the Xe-spallation product by a cosmic-ray muon, even though our experiment is taken place 1000-m-underground.
In the presentation, the new result of KamLAND-Zen 800 with 1 ton-year ^{136}Xe exposure will be presented with the estimation and the measurement of the long-lived Xe-spallation product.