Read more ...

An article was published in the journal Materials about development and manufacture of a pilot batch of the ultra-low background structural material for production of new-generation detectors to search for weakly interacting dark matter particles. The material obtained on the basis of polymethylmethacrylate and rare-earth metal gadolinium almost does not produce radiation background and can slow down and efficiently absorb neutrons. The team of scientists from the Mendeleev University of Chemical Technology (MUCT), Skobeltsyn Institute of Nuclear Physics of Moscow State University (SINP of MSU), Belgorod State University (BSU) and Dzhelepov Laboratory of Nuclear Problems (DLNP) has dealt with the task for several years. The research was performed within the international DarkSide-20k experiment, one of the largest projects on the dark matter particle search. The detector is due to start its operation in the underground low-background laboratory Gran Sasso in Italy in 2025−2026.

Read more ...

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.

Read more ...

For the first time in Russia, biological investigations into the effect of a low radiation background on complex model organisms have been carried out under the unique conditions of the low-background laboratory of the Baksan Neutrino Observatory (INR, RAS). The model was the fruit fly Drosophila melanogaster, a classic object for genetic research. The experiment showed that the low radiation background did not produce any effect on this model organism.

Read more ...

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.

Read more ...

Recently, the beam session at the ELSA accelerator of the University of Bonn has been completed. Scientists from the Sector of Low Temperatures (SLT) of the Dzhelepov Laboratory of Nuclear Problems were actively involved in it. The upgraded Crystal Barrel facility at the ELSA accelerator allows measuring double-polarization observables in reactions of photoproduction of neutral mesons. It is these measurements that are crucial to the search for “missing” resonances when studying the processes of photoproduction of mesons and hyperons on protons.

Read more ...

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 ...

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.

Read more ...

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.