https://doi.org/10.1140/epjc/s10052-013-2599-z
Letter
Search for anomalies in the ν e appearance from a ν μ beam
1
Laboratori Nazionali del Gran Sasso, INFN, Assergi, Italy
2
Dipartimento di Fisica e Astronomia, Università di Padova and INFN, Padova, Italy
3
Dipartimento di Fisica, Università di Pavia and INFN, Pavia, Italy
4
Politecnico di Milano and INFN, Milano, Italy
5
H. Niewodniczański Institute of Nuclear Physics, Polish Academy of Science, Kraków, Poland
6
Department of Physics and Astronomy, UCLA, Los Angeles, USA
7
Dipartimento di Scienze Fisiche, Università Federico II di Napoli and INFN, Napoli, Italy
8
INR RAS, Moscow, Russia
9
CERN, Geneva, Switzerland
10
National Centre for Nuclear Research, Otwock/Swierk, Poland
11
Institute of Physics, University of Silesia, Katowice, Poland
12
INFN Laboratori Nazionali di Frascati, Frascati, Italy
13
GSSI, L’Aquila, Italy
14
Institute for Radioelectronics, Warsaw University of Technology, Warsaw, Poland
15
INFN, Pisa, Italy
* e-mail: daniele.gibin@pd.infn.it
Received:
6
August
2013
Revised:
16
September
2013
Published online:
17
October
2013
We report an updated result from the ICARUS experiment on the search for ν μ →ν e anomalies with the CNGS beam, produced at CERN with an average energy of 20 GeV and traveling 730 km to the Gran Sasso Laboratory. The present analysis is based on a total sample of 1995 events of CNGS neutrino interactions, which corresponds to an almost doubled sample with respect to the previously published result. Four clear ν e events have been visually identified over the full sample, compared with an expectation of 6.4±0.9 events from conventional sources. The result is compatible with the absence of additional anomalous contributions. At 90 % and 99 % confidence levels, the limits to possible oscillated events are 3.7 and 8.3 respectively. The corresponding limit to oscillation probability becomes consequently 3.4×10−3 and 7.6×10−3, respectively. The present result confirms, with an improved sensitivity, the early result already published by the ICARUS Collaboration.
© Springer-Verlag Berlin Heidelberg and Società Italiana di Fisica, 2013