It has recently been announced discovery of the elementary particle richer in energy never observed: a neutrino detected off the coast of Sicily in the seabed of the Mediterranean Sea with the submarine telescope – still under construction – ARK (Astroparticle Research with Cosmics in the Abyss) of the project Km3net. Neutrines are extremely elusive elementary particles, of tiny mass and without electric charge that interact very little with the rest of the subject And for this they are extremely difficult to observe. So much so that to detect them, complexes “telescopes” for neutrinos in the seabed, as an ark, have been created.
THE’importance of this discovery He lies in the fact that the newly discovered particle is unique. Neutrines are fundamental particles to understand the astrophysical mechanisms that act in our universe (they are produced during nuclear reactions in the stars or following extreme events such as in active black holes or supernovae or the merger of neutron stars) and for the first time we have a proof of the fact that neutrinos with Energy so extreme They are possible.
The Origins of this record neutrino They are not yet certain, but it is believed that it may have been produced by the interaction of a very powerful cosmic radius with photons of cosmic background radiation, or by a gigantic supermassive black hole in the center of an active galaxy.
The energy of the record neutrin discovered off the coast of Sicily
The effects of the eliminous particle have been recorded the February 13, 2023but two years have occurred to get to scientific discovery, recently published in the magazine Nature. What has been observed it is certainly a neutrinand not only: its energy (which, simplifying, measures its speed approximate) is the highest ever measured for an elementary particle.
We are talking about 220 million billions of electronvolt: By comparison, it is an energy 30 times higher than that of the most energetic neutrinos ever observed so far, tens of billions of times higher than that of the neutrinos produced by the sun and about 30,000 times higher than the energies reached in Large Hadron Colliderthe most powerful particle accelerator in the world at CERN in Geneva.
How the richest cosmic neutrinus of energy ever observed was discovered
But how do we know it’s a neutrino? From its direction. But first we have to understand how a telescope for neutrinos as an ark. It is not a telescope as we generally mean it, that is, substantially a mirror aimed at heaven, but as a vast network of photomolteplies able to record weak light emissions in the seabed.
At these depths (Arca is located almost 3500 meters deep) there is no natural light. The light is emitted when a very energy particle crosses the water of the seabed. If this particle has a speed higher than the speed of light in the water (which is less than the speed of light in the voidwhich is the real maximum speed limit in the universe), the particle emits electromagnetic radiation due to a physical phenomenon called Cherenkov effect. This light is detected by the photomoltepiers of the underwater telescope, and according to the characteristics of this radiation it can be traced back to the type of particle that produced it, its energy and its direction.
In the case of the record neutrin, the light had been issued by a mussan elementary particle that can be produced by the interaction between a high energy neutrin and other particles. Then the telescope detects the light produced by a muone produced by our neutrino who “went to slam” with another particle. These are very indirect observations, and this is why two years were needed to reach the discovery.
The peculiarity of this muone is that it moved horizontally. It is something that you do not expect almost 3500 meters deep, unless it has been produced by a neutrino that has no problem to cross vast distances in the abysses, given its very scarce propensity to interact with the subject.
The possible origins of the neutrino discovered by the underwater telescope
The neutrine discovered in the Mediterranean is the first of its kind, so it is difficult to establish which astrophysical mechanism could have generated it. The main suspects at the moment, however, are two.
The first is a blazarthat is, a huge supermassive black hole that feeds an active galactic nucleus. The falling material in this black hole spirals around this cosmic monster, accelerating and warming up to breaking up into subatomic particles. The immense magnetic fields of the black hole make the rest, directing some of these particles in very powerful jets that dart in space almost at the speed of light. In these cases we talk about quasarand when his jets are facing the earth they take the most specific name of blazar. The record neutrin found by the Arca team could therefore have originated “a long time ago, in a distant galaxy” (the fans of Star Wars they will appreciate the quote). The astronomers were able to identify 12 Blazar who could have generated our neutrino.
The other hypothesis on the table is that of a cosmic extremely energetic (i.e. a lonely charged particle that darts in the cosmos at very high speed) who at some point in his journey interacted with a photon of the Cosmic background radiationthe residual “electromagnetic bath” of the Big Bang that can be observed in every direction in the microwave gang. This interaction can produce a small “rain” of very high energy neutrinos. Neutrines of this type have been theorized but never observed, so this could The first detection in history.
Because the discovery of this neutrino opens the doors on an almost unexplored universe
With a single event we cannot understand what the correct hypothesis is, but we must take into account that the KM3Net project is still under construction, so it will have a great way – with a little luck – to observe others ultra-energy neutrinos. Indeed, the fact of having had this detection while the telescope is not yet completed is certainly good omen!
The hope of astronomers is that neutrines can become, with technological progress, a New observation channel of our universe in addition to the light, which was the only source of information on the cosmos.
