Advances in High Energy Physics

Review Article

Challenges in Double Beta Decay

Table 6

EXO-200 136Xe ( = 2457 keV) running experiment
FWHM 96 keV
EXPOSURE 32.5 kg (136Xe) × yr
MASS 79 kg of 136Xe (LXe fiducial volume of 98.5 kg)
BKG  
 Rejection Single-site versus multisite events separation + fiducial volume + rejection through light/charge ratio
 Rate ( ) × 10−3 counts/(keV kg yr)
 Sources Bi (localized outside the TPC, therefore contributing mainly through its 2448 keV  ), 232Th and 238U in the TPC vessel (2448 keV from Bi and 2615 keV from Tl)
<1.6 × 1525 yr at 90% C.L. [160]
1.2 × 1026 yr in 5 years (with the same background, detection efficiency (82.5%), and active mass of [160])