Double Beta Decay Research — Present and Future

Abstract

During the last fifteen years remarkable results have been obtained in double beta decay investigation, level of which looked like unattainable during the whole history of this research beginning from the theoretical prediction of 2β decay by M. Goeppert-Mayer ¹ in 1935 and the first experimental work by E. Fireman ² in 1948: half-life limit of greater than 10²⁴ y for neutrinoless (0ν) 2β decay of ⁷⁶Ge ^3–6; large scale experiments on ⁷⁶Ge with enriched HP Ge detectors ^5,6; half-life limits of greater than 10²³ y for 0ν2β decay of ¹³⁶Xe ⁷ and 10²² y for ⁸²Se ⁸, ¹⁰⁰Mo ⁹, ¹¹⁶Cd ¹⁰ and ¹³⁰Te ¹¹; observation of the two neutrino (2ν) 2β decay of ⁷⁶Ge ^4–6, ⁸²Se ⁸, ¹⁰⁰Mo ^12–14, ¹¹⁶Cd ^15–17 and ¹⁵⁰Nd ^{13, 18} in direct counting experiments; progress in the theoretical interpretation of double beta decay ^19–21.