Authors: George Rajna
Neutrinos are tricky. Although trillions of these harmless, neutral particles pass through us every second, they interact so rarely with matter that, to study them, scientists send a beam of neutrinos to giant detectors. And to be sure they have enough of them, scientists have to start with a very concentrated beam of neutrinos. To concentrate the beam, an experiment needs a special device called a neutrino horn.  The ultra-low background KamLAND-Zen detector, hosted by research institutes inside and outside Japan demonstrates the best sensitivity in the search for neutrinoless double-beta decay, and sets the best limit on the effective Majorana neutrino mass.  Now, researchers from the University of Tokyo, in collaboration with a Spanish physicist, have used one of the world's most powerful computers to analyse a special decay of calcium-48, whose life, which lasts trillions of years, depends on the unknown mass of neutrinos. This advance will facilitate the detection of this rare decay in underground laboratories.  To measure the mass of neutrinos, scientists study radioactive decays in which they are emitted. An essential ingredient is the decay energy which corresponds to the mass difference between the mother and daughter nuclei. This decay energy must be known with highest precision. A team of scientists now succeeded to resolve a severe discrepancy of the decay energy for the artificial holmium (Ho) isotope with mass number 163.  The Weak Interaction transforms an electric charge in the diffraction pattern from one side to the other side, causing an electric dipole momentum change, which violates the CP and Time reversal symmetry.
Comments: 19 Pages.
[v1] 2016-08-24 13:25:16
Unique-IP document downloads: 24 times
Add your own feedback and questions here:
You are equally welcome to be positive or negative about any paper but please be polite. If you are being critical you must mention at least one specific error, otherwise your comment will be deleted as unhelpful.