Agostini, M;
Altenmüller, K;
Appel, S;
Atroshchenko, V;
Bagdasarian, Z;
Basilico, D;
Bellini, G;
... Zuzel, G; + view all
(2023)
Methodology used in Borexino for the identification of cosmogenic long-time decay background.
In:
Low Radioactivity Techniques 2022 (LRT 2022): Proceedings of the 8th International Workshop on Low Radioactivity Techniques.
AIP Publishing: Rapid City, SD, USA.
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Abstract
Borexino was a liquid scintillator detector situated underground in the Laboratori Nazionali del Gran Sasso in Italy, officially decommissioned in October 2021. Its successful and renowned physics program covered the study of solar neutrinos program and spans also across geo-neutrinos and neutrino physics. Within its solar program, Borexino successfully measured neutrinos from the fusion processes in the pp chain and CNO cycle. For the detection of pep and CNO neutrinos, an especially important background is formed by the cosmogenic radio-isotope 11C that is produced by muon spallation of 12C nuclei in the scintillator. Given the relatively long lifetime (30 mins) and high rate (30 cpd per 100 ton), specific signal identification is not possible. Borexino developed dedicated veto strategies in the data analysis phase to allow the detection of pep and CNO neutrinos. The results presented so far by Borexino relied upon a Three-Fold Coincidence (TFC) technique that exploits the time and space correlation of muons, spallation neutrons, and radioactive 11C decays. This method has conservative assumptions during critical data-taking periods, such as during a board saturation case or between runs, which causes a loss of data exposure. Therefore, a new algorithm is devised to relax these TFC assumptions and deal with the critical periods by searching for space-time correlated bursts of 11C events produced in cascade by the spallation. In this work, we present the state of the art of the TFC, the new algorithm working, and highlight the performance of their combination to deal with the 11C background. Moreover, this method finds a general application in low radioactivity Borexino-like underground experiments when dealing with any background having a decay time too long to be identified by the triggers.
| Type: | Proceedings paper |
|---|---|
| Title: | Methodology used in Borexino for the identification of cosmogenic long-time decay background |
| Event: | 8th International Workshop on Low Radioactivity Techniques (LRT 2022) |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1063/5.0161149 |
| Publisher version: | https://doi.org/10.1063/5.0161149 |
| Language: | English |
| Additional information: | This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | Radioactive decay, Scintillation detectors, Solar neutrinos, Leptons, News and events |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10183326 |
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