Akademska digitalna zbirka SLovenije - logo
E-viri
Recenzirano Odprti dostop
  • Identification of the cosmo...
    M. Agostini; K. Altenmüller; S. Appel; V. Atroshchenko; Z. Bagdasarian; D. Basilico; G. Bellini; J. Benziger; R. Biondi; D. Bravo; B. Caccianiga; F. Calaprice; A. Caminata; P. Cavalcante; A. Chepurnov; D. D’Angelo; S. Davini; A. Derbin; A. Di ZGiacintio; V. Di Marcello; X. F. Ding; A. Di Ludovico; L. Di Noto; I. Drachnev; A. Formozov; D. Franco; C. Galbiati; C. Ghiano; M. Giammarchi; A. Goretti; A. S. Göttel; M. Gromov; D. Guffanti; Aldo Ianni; Andrea Ianni; A. Jany; D. Jeschke; V. Kobychev; G. Korga; S. Kumaran; M. Laubenstein; E. Litvinovich; P. Lombardi; I. Lomskaya; L. Ludhova; G. Lukyanchenko; L. Lukyanchenko; I. Machulin; J. Martyn; E. Meroni; M. Meyer; L. Miramonti; M. Misiaszek; V. Muratova; B. Neumair; M. Nieslony; R. Nugmanov; L. Oberauer; V. Orekhov; F. Ortica; M. Pallavicini; L. Papp; L. Pelicci; Ö. Penek; L. Pietrofaccia; N. Pilipenko; A. Pocar; A. Porcelli; G. Raikov; M. T. Ranalli; G. Ranucci; A. Razeto; A. Re; M. Redchuk; A. Romani; N. Rossi; S. Schönert; D. Semenov; G. Settanta; M. Skorokhvatov; A. Singhal; O. Smirnov; A. Sotnikov; Y. Suvorov; R. Tartaglia; G. Testera; J. Thurn; E. Unzhakov; A. Vishneva; R. B. Vogelaar; F. von Feilitzsch; M. Wojcik; M. Wurm; S. Zavatarelli; K. Zuber; G. Zuzel

    The European physical journal. C, Particles and fields, 12/2021, Letnik: 81, Številka: 12
    Journal Article

    Abstract Cosmogenic radio-nuclei are an important source of background for low-energy neutrino experiments. In Borexino, cosmogenic $$^{11}$$ 11 C decays outnumber solar pep and CNO neutrino events by about ten to one. In order to extract the flux of these two neutrino species, a highly efficient identification of this background is mandatory. We present here the details of the most consolidated strategy, used throughout Borexino solar neutrino measurements. It hinges upon finding the space-time correlations between $$^{11}$$ 11 C decays, the preceding parent muons and the accompanying neutrons. This article describes the working principles and evaluates the performance of this Three-Fold Coincidence (TFC) technique in its two current implementations: a hard-cut and a likelihood-based approach. Both show stable performances throughout Borexino Phases II (2012–2016) and III (2016–2020) data sets, with a $$^{11}$$ 11 C tagging efficiency of $$\sim 90$$ ∼ 90  % and $$\sim $$ ∼  63–66 % of the exposure surviving the tagging. We present also a novel technique that targets specifically $$^{11}$$ 11 C produced in high-multiplicity during major spallation events. Such $$^{11}$$ 11 C appear as a burst of events, whose space-time correlation can be exploited. Burst identification can be combined with the TFC to obtain about the same tagging efficiency of $$\sim 90\%$$ ∼ 90 % but with a higher fraction of the exposure surviving, in the range of $$\sim $$ ∼  66–68 %.