Fri, 07/19/2013 - 11:14

Neutrinos are the most elusive particles as they have extremely weak interactions with all other particles. They have rather unique properties and are even expected to be identical with their own antiparticles. So far this property is, however, not experimentally verified even though many studies of neutrinos undertaken over the last 60 years have already boosted our understanding of elementary particle physics. Now scientists from the GERDA collaboration have obtained new strong limits for the so-called neutrino-less double beta decay which tests if neutrinos are their own antiparticles. The result has various important implications for cosmology, astrophysics and particle physics and it adds information about neutrino masses.

Besides photons, neutrinos are the most abundant particles in the Universe. They are often called `ghost particles’, because they interact extremely weakly with matter. They are therefore an invisible, but very important component of the Universe and could carry as much mass as all other known forms of matter put together − albeit traveling at almost the speed of light over vast distances. Their tiny mass also has important consequences for the structures in the Universe and they are a driving element in the explosion of Supernovae. Yet their most remarkable and important property was proposed by Ettore Majorana in the 1930s: Unlike all other particles that form known matter around us, neutrinos may be their own antiparticles.

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