Abstract
Data from five recent double-β-decay experiments were combined in a single spectrum equivalent to counting for 0.4 yr with 1770- fiducial volume of Ge. The composite spectrum was analyzed using an approximate analytical form of the likelihood function. The maximum likelihood 68%-C.L. values for the half-life and Majorana ν mass are Ge)≳4.1× yr and 〈〉≲2.4 eV, respectively, when accounting for the slight depression in the spectrum, and 2.4× yr and 〈〉≲3.2 eV when neglecting the depression. It is clearly demonstrated that experiments with current levels of background will soon reach their point of diminishing returns.
- Received 14 July 1986
DOI:https://doi.org/10.1103/PhysRevD.35.1713
©1987 American Physical Society