Beta Decay Of 136Xe Research Articles

Limits on neutrinoless double beta decay in 136Xe with a time projection chamber

A xenon Time Projection Chamber with an active volume of 207 liters has been built to study 0ν and 2ν double beta decay in 136 Xe. Data were taken in the Gotthard Underground Laboratory, with 5 atm of xenon enriched to 62.5% in 136 Xe. From 4861 hours of data, no evidence has been found for the 0 + → 0 + transition. Half-life limts of T 1 2 0ν (0 + → 0 + ) > 2.7(5.2) × 10 23 years in the mass mechanism mode, and T 1 2 0ν (0 + → 0 + ) > 1.9(3.5) × 10 23 years in the right-handed currents mode, at the 90(68)% C.L., were derived. Upper limits for the Majorana neutrino mass parameter were deduced.

First 0 nu half-life limit from the Gotthard xenon time projection chamber

A xenon time-projection-chamber (TPC) with an active volume of 207 liters has been built to study 0 nu and 2 nu double beta decay in 136Xe. The TPC has been installed in the Gotthard Tunnel Underground Laboratory, and is currently taking data with 5 atm of xenon enriched in 62.5% 136Xe. The first 166 hours of data are presented. Based on this data set, the authors deduce a half-life limit of T12/0 nu (0+ to 0+)>6.2*1021 years for the 0 nu mode, at a 90% CL.