https://doi.org/10.1140/epja/i2019-12911-3
Regular Article - Experimental Physics
First direct search for 
and 
decay of 144Sm and 
decay of 154Sm
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, National Academy of Sciences of Ukraine, 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
Dipartimento di Fisica, Università di Roma “La Sapienza”, I-00185, Rome, Italy
7
INFN, Laboratori Nazionali del Gran Sasso, I-67100, Assergi (AQ), Italy
8
CSNSM, Univ. Paris-Sud, CNRS/IN2P3, Université Paris-Saclay, 91405, Orsay, France
* e-mail: rita.bernabei@roma2.infn.it
Received:
15
July
2019
Accepted:
4
October
2019
Published online:
14
November
2019
The first direct search for the double electron capture (
) and the electron capture with positron emission (
) in 144Sm to the ground state and to the excited levels of 144Nd was realized by measuring --over 1899h-- a 342g sample of highly purified samarium oxide (Sm2O3) with the ultra-low background HP-Ge 
spectrometer GeCris (465cm3) at the STELLA facility of the Gran Sasso National Laboratory (LNGS). No effect was observed and half-life limits were estimated at the level of 
yr (90% C.L.). Moreover, for the first time half-life limits of the double beta (
) decay of 154Sm to several excited levels of 154Gd have been set; they are at the level of 
yr (90% C.L.).
© Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature, 2019
