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The results on the search for the neutrinoless double-beta (0νββ) decay of 76Ge in the GERDA (GERmanium Detector Array) experiment have been published in the recent issue of Physical Review Letters. Moreover, the paper has been selected to be a PRL Editors' Suggestion. No signal has been observed, but all goals of the final phase of the experiment have been achieved.

Read more ...All living things on Earth originated and evolved in a natural radiation background environment. That is why the reaction of living objects to the almost complete suppression of the natural radiation background in deep underground neutrino laboratories is of great interest to biologists across the world over many years. In November 2019, the experiments conducted by the Molecular Genetics Group (DLNP, JINR), along with the Laboratory of Low-Background Research (BNO, INR, RAS), got underway in the unique environment of the DULB-4900 low-background laboratory (Neutrino village, Kabardino-Balkaria) located 4 km away from the tunnel entrance about two kilometers deep under the Andirchi peak (3937 m).

Read more ...In the November issue of the European physical journal  EPJ C, a paper of the Borexino collaboration was published about detector sensitivity to CNO neutrinos with respect to the strategy which sets limits on two main backgrounds in measurements—neutrinos from the pp chain and bismuth-210 decay events in scintillator. Considering a neutrino flux predicted by one of the standard models of the Sun, Borexino was sensitive to CNO neutrinos during the 1000-day exposure at the level of above 3σ. With the same considerations, the precision of the CNO-neutrino flux measurement is 23% with a restriction on the rate of bismuth-210 event counting at the level of 1.5 events a day for 100 t of scintillator. For upcoming experiments with a higher precision of the CNO-neutrino flux measurement, the probability was evaluated to identify a more reliable model of the Sun, of high or low metallicity. This article complements the one recently published in Nature.

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The MINOS+ and Daya Bay neutrino experiments combined results to produce the most stringent test yet for the existence of sterile neutrinos.

An international group of more than 260 scientists have produced one of the most stringent tests for the existence of sterile neutrinos to date. The scientists from two major international experimental groups, Daya Bay in China and the MINOS+ at the Department of Energy's Fermilab, are reporting results in Physical Review Letters (Phys. Rev. Lett. 125, 071801 (2020)) ruling out oscillations into one sterile neutrino as the primary explanation for unexpected observations in the recent LSND and MiniBooNE experiments.

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On Saturday, 12 December 2020, a special ceremony of the shutdown of the facility of the Daya Bay international neutrino experiment will take place. Scientists will proceed with final data analysis.

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Can the years spent in ideal conditions eliminate natural selection that affected living organisms for millions of years? It is believed that Homo sapiens is there for about 1600—1800 generations. And with a 25-year-long human generation, it would take hundreds and thousands of years to answer this question. However, using model organisms with a short life cycle but with the life and adaptation processes common for different organisms can give some answers.

Drosophila melanogaster, a fruit fly, is widely used as a model object for studying the way living organisms adapt to environmental changes and inherit certain traits.

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The international Borexino Collaboration has announced the first observation of neutrinos from the CNO process in the Sun, which experimentally confirms the second mechanism for energy generation in stars. Earlier, only neutrinos from the proton–proton cycle were observed. This discovery is highly important for astrophysics since in stars more massive than the Sun energy is mainly produced through the CNO cycle. The results of the investigation are published in Nature.

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This week, the Neutrino-2020 conference is underway, the most authoritative event among the scientists involved in neutrino physics. The conference is held every two years, this year online. Traditionally, the main results of the studies conducted by physicists during the previous years are introduced at the conference, which explains the vast target audience. The last conferences were attended by about one thousand participants.

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Neutrino geophysics has evolved to a separate discipline not so long ago. This rapidly developing branch of science at the intersection of geology, geophysics and particle physics examines the Earth’s interior by observing antineutrino fluxes produced by the decay of radioactive elements in the Earth’s crust and mantel. The contribution of radioactive decays to the total heat release of the Earth (radiogenic heat) determines the heat history of the Earth and restricts its geophysical models.

Read more ...Scientists involved in the Borexino collaboration have presented new results of the measurement of neutrinos originating from the interior of the Earth. The Borexino detector is located 1,400 metres below the Earth's surface in the Gran Sasso massif near Rome. The elusive "ghost particles" rarely interact with matter, making their detection extremely difficult. With this update, the researchers have now been able to access almost twice as many events as in the previous analysis of the data. The results provide an exclusive insight into processes and conditions in the Earth's interior that remain puzzling to this day.