Physics first saw neutrino collides with the nucleus of an atom

© Illustration RIA Novosti . Alina Planinata the artist imagined the collision of neutrinos and the nucleus of an atomPhysics first saw neutrino collides with the nucleus of an atom© Illustration RIA Novosti . Alina Polyanina

Russian and foreign physicists were able to capture collisions of neutrinos with atomic nuclei, the observation of which confirmed the generally accepted theory about their behavior, according to a paper published in the journal Science.

«Why is the discovery we made just today, not 43 years ago? What happens during this collision, it is almost impossible to notice. Overall, its effects can be compared with what happens with the bowling ball when it hits the ball ping-pong table. Daniel Friedman, who discovered this interaction at the level of the theory, wrote that the rare frequency of collisions and noise are unlikely to see it,» says Juan collar (Juan Collar) from the University of Chicago (USA).

Neutrinos are tiny elementary particles that «communicate» with the surrounding matter only through gravity and the so-called weak interactions, which manifests itself only at distances significantly smaller than the nucleus of an atom. In the middle of the last century scientists have discovered three types of particles — Tau, muon and electron neutrinos and their «evil twins»-neutrino.

Neutrinos, due to their small size and unusual properties, virtually always pass through all forms of matter – if you take a bar of lead in length, light year, equal to roughly 1.5 trillion kilometers, and pass through it a stream of these particles, only half of them reaches its end. For this reason, neutrinos are often called particles-ghosts.

However, collisions of neutrinos and atoms still needs to happen under certain conditions, as found by the famous American physicist Daniel Friedman in 1974, neutrinos will interact with the nucleus of the atom, simultaneously exchanging with all of its protons and neutrons, the so-called Z bosons, carriers of momentum.

As a result, neutrinos «bounce» from the nucleus of an atom and all — atom will get additional impetus and begin to move in the opposite direction similar to what happens with colliding billiard balls.

Neutrinos, as it turned out, can face with matter in other ways, however, such «collective» cooperation between all neutrons and protons inside nucleus and a single neutrino, as shown by calculations, Friedman, needs to happen more often. Despite this, scientists have unsuccessfully searched for them for over 40 years.

Size doesn’t matter

This problem was solved by Kollar and his colleagues, including Russian physicists from the Kurchatov Institute, Institute of theoretical and experimental physics and several other scientific organizations, thanks to an unorthodox approach to «capture» neutrinos – they did not increase the size of the detectors, as scientists usually do when observing particles-ghosts, and reduced it.

As noted by scientists, increasing the «accuracy» and intense source of neutrinos allows you to get a much greater frequency of collisions of particles with atoms and increase the probability of detecting traces of them in comparison with the increase in size and weight of the detector.

Watching the glow of the crystals, inside which there are atoms of cesium, for 15 months, physicists have managed to prove that these flashes of light occur in the collision of beams of neutrinos with nuclei of the metal and transfer some of the kinetic energy of the «particles-ghosts» stationary cesium.

These clashes, as the researchers note, in General, was exactly as predicted by the Standard model. On the other hand, Kollar and his colleagues believe that further observation of such clashes may bring scientists on the traces of «new physics», and also will allow to understand the role neutrinos played in the birth of supernovae and other cataclysmic events in the cosmos.