Open AccessIdentification of the cosmogenic 11C background in the solar neutrino experiment Borexino
Author(s) -
A. Porcelli
Publication year - 2021
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/2156/1/012205
Subject(s) - borexino , neutrino , physics , scintillator , spallation , nuclear physics , solar neutrino , muon , neutron , particle physics , detector , neutrino oscillation , optics
Borexino is a liquid scintillator detector situated underground in the Laboratori Nazionali del Gran Sasso in Italy. Its physics program evolves around the study of solar and geo-neutrinos. By now, Borexino has measured neutrinos from the fusion processes in the pp chain and CNO cycle. Especially for the detection of pep and CNO neutrinos, an important background is formed by the cosmogenic radio-isotope 11 C that is produced by muon spallation of 12 C nuclei in the scintillator. Given the comparatively long life time (30 mins) and high rate (30 cpd and 100 ton), dedicated veto strategies had to be developed to permit the detection of pep and CNO neutrinos. The present contribution presents two veto methods. One is the well-established Three-Fold Coincidence (TFC) technique that relies on time and space correlation of muons, spallation neutrons, and radioactive 11 C decays; it has been used in different implementations in all former Borexino analyses. In addition, a newly devised algorithm searching for time-correlated bursts of 11 C events will be presented, highlighting as well the potential gain from a combined application with the TFC technique.