https://doi.org/10.1140/epja/i2017-12360-0
Regular Article - Experimental Physics
New limits on 
, 
and 
decay of 136Ce and 138Ce with deeply purified cerium sample
1
INFN sezione Roma “Tor Vergata”, I-00133, Rome, Italy
2
Dipartimento di Fisica, Università di Roma “Tor Vergata”, I-00133, Rome, Italy
3
Institute for Nuclear Research, 03028, Kyiv, Ukraine
4
National University of Life and Environmental Sciences of Ukraine, 03041, Kyiv, Ukraine
5
INFN sezione Roma, I-00185, Rome, Italy
6
INFN, Laboratori Nazionali del Gran Sasso, I-67100, Assergi (AQ), Italy
7
Dipartimento di Fisica, Università di Roma “La Sapienza”, I-00185, Rome, Italy
* e-mail: rita.bernabei@roma2.infn.it
Received:
3
May
2017
Accepted:
25
July
2017
Published online:
29
August
2017
A search for double electron capture (
), electron capture with positron emission (
), and double positron emission (
) in 136Ce and 138Ce was realized with a 465 cm3 ultra-low background HP Ge 
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 
quanta expected in double 
decay of the cerium isotopes. New improved half-life limits were set on different modes and channels of double decay of 136Ce and 138Ce at the level of 
yr.
© SIF, Springer-Verlag GmbH Germany, 2017
