Evidence of the double beta decay of zirconium-96 measured in 1.8 X 10(9) year-old zircons - art. no. 024308

Molybdenum extracted from geologically old zircons shows evidence for enhan ced levels of Mo-96, resulting from the double beta decay of Zr-96. Evidenc e of nuclear fission in Mo-95, Mo-97, Mo-98, and Mo-100 extracted from the old zircons accompanies the double beta decay of Zr-96, and is comparable i n magnitude to the excess Mo-96. Zircons are excellent minerals for an expe riment of this nature, since zircon U-Pb geochronology demonstrates that zi rcons have remained as closed isotopic systems over eons of time. The exper imental data indicate that the half-life of Zr-96 double beta decay is (9.4 +/-3.2) x 10(18) yr and is in good agreement with the theoretically predict ed half-life for the Zr-96 decay to Mo-96 occurring as a two neutrino decay .