Results of the experiment on the search for double beta decay of 136Xe, 134Xe and 124Xe

Nuclear structure calculation of? + ? +,? +/EC and EC/EC decay matrix elements

“…Combining the coefficients C~y with available experimental limits on 0 vfl +/EC and 0 vfl + fl + decay half lives [33][34][35] the upper bounds on (m~), (2) and (i/) summarized in Table 4 candidates [2][3][4][5][6][7]. Consequently also the limits on (my), (~) and (I/) are far less stringent.…”

“…Limits on (m~), (2) and (r/) deduced from the nonobservation of 0 v fl + fl + and 0 v fl +/EC decay. Experimental data taken from [33][34][35]. Upper values given are those obtained letting the other two parameters vary arbitrarily, whereas the lower ones are "on axis" assuming the other two parameters to be equal to zero a B + B + decays ~2 and Cruz and Cn~ by ~ also, the maximum allowed value of (2) would be more restrictive by (exactly) a factor of ~.)…”

“…These numbers should be compared to existing experimental limits [33][34][35], for completeness also given in Table 1. On the other hand, advanced Bfl decay exeriments might improve these limits by many orders of magnitude.…”

Searches for double beta decay ofXe134with EXO-200

“…3, along with the fitted 134 Xe 0νββ from the other search. The limits presented in this paper increase the sensitivity relative to those available in the current literature by 5 orders of magnitude for the 2νββ search [10], while the limit set for 0νββ is nearly twice as stringent as the one in Ref. [12].…”

“…The current experimental limit for the half-life of 2νββ in 134 Xe is T 2νββ 1=2 > 1.1 × 10 16 yr at 68% C.L. [10], while theoretical predictions put it in the range of ∼10 24 -10 25 yr [11]. On the other hand, more recent searches set the most stringent limit for the 0νββ half-life at T 0νββ 1=2 > 5.8 × 10 22 yr at 90% C.L.…”