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., ...More

European Physical Journal C, vol.80, no.8, 2020 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 80 Issue: 8
  • Publication Date: 2020
  • Doi Number: 10.1140/epjc/s10052-020-8160-y
  • Journal Name: European Physical Journal C
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Communication Abstracts, INSPEC, zbMATH, Directory of Open Access Journals
  • Middle East Technical University Affiliated: Yes


© 2020, The Author(s).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 cc¯ 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 ντ 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.