Day 3 Summaries
The morning session saw presentations of results from a wide spectrum of experiments different in scope and techniques.
The first talk, by Giampaolo Bellini, discussed the Borexino experiment. Among the results of that experiment are a direct experimental evidence that the nuclear reactions supporting the Sun shining belong to the pp cycle; the oscillation in vacuum has been observed experimentally and the related electron neutrino survival probability has been measured. The Borexino data also reached a 5.9 sigma evidence of a flux of geo-neutrinos. As a by-product, several best limits have been obtained. Borexino will take data until 2020-2022, in an effort to measure the CNO flux.
The MEG experiment was described by Fabrizio Cei. MEG looked for muon decays to electron and photon at the Paus Scherrer Institute. The collected data allowed the collaboration to set an upper limit in the branching ratio at 4.2×10^-13 at 90% Confidence Level.
Bruna Bertucci (see picture, right) discussed the AMS experiment in a talk that was not made available yet in the conference web site.
The LUNA project was discussed by Alessandra Guglielmetti. The underground accelerator, located in the Gran Sasso laboratory, aims at studying neutrino astrophysics through detailed studies of nuclear reactions in a very low-background environment. The predicted start of operation is 2019.
Noah Oblath discussed the study of beta decays of Tritium for the direct measurement of neutrino mass. Here the usual method has relied on the measurement of the endpoint of the energy spectrum of the emitted electron. A new technique relies on “Cyclotron Radiation Emission Spectroscopy” (CRES), where the Tritium gas is enclosed in a volume with a magnetic field, and cyclotron radiation is detected with antennas. Phase 1 is completed, with a proof of the detection of the cyclotron frequency. The final goal (phase 4, with atomic Tritium) is expected to provide a sensitivity to 40 meV on neutrino mass.
The KamLAND experiment was discussed by Junpei Shirai (a more historical discussion of this project was given on the first day of the conference in the “Breakthrough prize” session). KamLAND is the first O(100)km long baseline reactor neutrino experiment using a 1000-ton liquid scintillator detector. It made the first observation of the reactor neutrino disappearance and the oscillatory pattern in the spectrum showing the clear evidence of the neutrino oscillation. KamLAND has helped solving the solar neutrino problem and determined the oscillation parameter with great precision. The experiment made the first challenge of the geo-neutrino detection opening the Neutrino-Geoscience. It now continues geo-neutrino measurement and neutrino astronomy, and promotes the KamLAND-Zen project for 0νββ search of 136Xe nuclei with an ultra-low background facility.
For the last two talks of Wednesday morning, for the time being I can only offer pictures of the speakers, Stefan Schoenert and Stefano Pozzi – see below.
In the afternoon there were many more interesting talks. They will be summarized below once the slides are uploaded on the web site of the conference.