# First observation of a tau neutrino charged current interaction with charm production in the OPERA experiment OPERA Collaboration

Agafonova, N, Aleksandrov, A, Anokhina, A, Aoki, S, Ariga, A, Ariga, T, Bertolin, A, Bozza, C, Brugnera, R, Buonaura, A
et al (show 118 more authors) (2020) First observation of a tau neutrino charged current interaction with charm production in the OPERA experiment OPERA Collaboration. EUROPEAN PHYSICAL JOURNAL C, 80 (8).

 Text 1912.11012v3.pdf - Author Accepted Manuscript Download (2MB) | Preview

## Abstract

An event topology with two secondary vertices compatible with the decay of short-lived particles was found in the analysis of neutrino interactions in the Opera target. The observed topology is compatible with tau neutrino charged current (CC) interactions with charm production and neutrino neutral current (NC) interactions with $c\overline{c}$ pair production. However, other processes can mimic this topology. A dedicated analysis was implemented to identify the underlying process. A Monte Carlo simulation was developed and complementary procedures were introduced in the kinematic reconstruction. A multivariate analysis technique was used to achieve an optimal separation of signal from background. Most likely, this event is a $\nu_{\tau}$ CC interaction with charm production, the tau and charm particle decaying into 1 prong and 2 prongs, respectively. The significance of this observation is evaluated.

Item Type: Article 10 pages, 7 figures; Editors: Marco Roda, Chiara Sirignano and Gabriele Sirri hep-ex, hep-ex Symplectic Admin 08 Oct 2020 08:28 18 Jan 2023 23:30 10.1140/epjc/s10052-020-8160-y https://livrepository.liverpool.ac.uk/id/eprint/3103669