A step toward CNO solar neutrino detection in liquid scintillators

作者：Villante F L^*; Ianni A; Lombardi F; Pagliaroli G; Vissani F

来源：Physics Letters B, 2011, 701(3): 336-341.

DOI：10.1016/j.physletb.2011.05.068

• Solar neutrinos
• Neutrino detectors

The detection of CNO solar neutrinos in ultrapure liquid scintillator detectors is limited by the background produced by bismuth-210 nuclei that undergo beta-decay to polonium-210 with a lifetime of similar to 7 days. Polonium-210 nuclei are unstable and decay with a lifetime equal to similar to 200 days emitting alpha particles that can be also detected. In this Letter, we show that the Bi-210 background can be determined by looking at the time evolution of alpha-decay rate of Po-210, provided that alpha particle detection efficiency is stable over the data acquisition period and external sources of Po-210 are negligible. A sufficient accuracy can be obtained in a relatively short time. As an example, if the initial Po-210 event rate is similar to 2000 cpd/100 ton or lower, a Borexino-like detector could start discerning CNO neutrino signal from Bi-210 background in Delta t similar to 1 yr.

• 出版日期2011-7-11