Monday, March 15, 2010

Borexino Detects Geoneutrinos

More detection of geoneutrinos that was probably first observed at KamLAND a few years ago. This time, it appears to be a cleaner signal detected at Borexino experiment at the Italy's Gran Sasso National Laboratory {link may be available for free only for a limited time}. The preprint of the paper can be found on ArXiv.

The experiment ran for two years ending December 2009 and the Borexino collaboration (about 80 researchers from six countries) says that it detected 9.9 geoneutrino events, with uncertainties of +4.1 and –3.4. Spokesman Gianpaolo Bellini of the University of Milan says that the result also appears to rule out a controversial hypothesis that a large part of Earth's heat is produced by a naturally occurring nuclear reactor fuelled by uranium in the planet's core.

It's interesting how the difficult task here is not detecting neutrinos, but rather to be able to distinguish which ones come from where. One probably has to use both the energy distribution, time dependence, and path reconstruction to be able to discriminate the geoneutrinos from the others.


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