New limits on 2 epsilon, epsilon beta(+) and 2 beta(+) decay of Ce-136 and Ce-138 with deeply purified cerium sample

作者：Belli P; Bernabei R; Boiko R S; Cappella F; Cerulli R; Danevich F A; Incicchitti A; Kropivyansky B N; Laubenstein M; Mokina V M; Polischuk O G; Tretyak V I

来源：European Physical Journal A, 2017, 53(8): 172.

DOI：10.1140/epja/i2017-12360-0

A search for double electron capture (2 epsilon), electron capture with positron emission (epsilon beta(+)), and double positron emission (2 beta(+)) in Ce-136 and Ce-138 was realized with a 465 cm(3) ultra-low background HP Ge gamma spectrometer over 2299 h at the Gran Sasso underground laboratory. A 627 g sample of cerium oxide deeply purified by liquid-liquid extraction method was used as a source of gamma quanta expected in double beta decay of the cerium isotopes. New improved half-life limits were set on different modes and channels of double beta decay of Ce-136 and Ce-138 at the level of T-1/2 > 10(17) - 10(18) yr.

• 出版日期2017-8-29