https://doi.org/10.1140/epjc/s10052-016-4454-5
Regular Article - Experimental Physics
Limit on the radiative neutrinoless double electron capture of 
Ar from GERDA Phase I
1
INFN Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, Assergi, Italy
2
INFN Laboratori Nazionali del Sud, Catania, Italy
3
Institute of Physics, Jagiellonian University, Kra ków, Poland
4
Institut für Kern- und Teilchenphysik, Technische Universität Dresden, Dresden, Germany
5
Joint Institute for Nuclear Research, Dubna, Russia
6
European Commission, JRC-Geel, Geel, Belgium
7
Max-Planck-Institut für Kernphysik, Heidelberg, Germany
8
Dipartimento di Fisica, Università Milano Bicocca, Milan, Italy
9
INFN Milano Bicocca, Milan, Italy
10
Dipartimento di Fisica, Università degli Studi di Milano e INFN Milano, Milan, Italy
11
Institute for Nuclear Research of the Russian Academy of Sciences, Moscow, Russia
12
Institute for Theoretical and Experimental Physics NRC “Kurchatov Institute”, Moscow, Russia
13
National Research Centre “Kurchatov Institute”, Moscow, Russia
14
Max-Planck-Institut für Physik, Munich, Germany
15
Physik Department and Excellence Cluster Universe, Technische Universität München, Munich, Germany
16
Dipartimento di Fisica e Astronomia dell’Università di Padova, Padua, Italy
17
INFN Padova, Padua, Italy
18
Physikalisches Institut, Eberhard Karls Universität Tübingen, Tübingen, Germany
19
Physik Institut der Universität Zürich, Zurich, Switzerland
20
University of Pennsylvania, Philadelphia, PA, USA
21
Moscow Institute of Physics and Technology, Moscow, Russia
22
International University for Nature, Society and Man “Dubna”, Dubna, Russia
23
LAL, CNRS/IN2P3, Université Paris-Saclay, Orsay, France
* e-mail: gerda-eb@mpi-hd.mpg.de
Received:
19
May
2016
Accepted:
12
October
2016
Published online:
28
November
2016
Neutrinoless double electron capture is a process that, if detected, would give evidence of lepton number violation and the Majorana nature of neutrinos. A search for neutrinoless double electron capture of Ar has been performed with germanium detectors installed in liquid argon using data from Phase I of the GERmanium Detector Array (Gerda) experiment at the Gran Sasso Laboratory of INFN, Italy. No signal was observed and an experimental lower limit on the half-life of the radiative neutrinoless double electron capture of Ar was established: 
3.6 
10
years at 90% CI.
© The Author(s), 2016
