Modern Physics

Neutrinos

Neutrinos are particles that arise from beta decay and, after photons, are the most abundant type of element in the entire universe.

Every second, the Sun emits billions of neutrinos that hit the entire surface of the Earth.
Neutrinos are subatomic particles with no electrical charge and with a mass much less than that of an electron. Indicated by the Greek letter ν (nu), these elements cannot be confused with neutrons, a type of uncharged particle that makes up the nucleus of atoms .

How were neutrinos discovered?

The discovery of neutrinos was made possible through observation and understanding of the beta decay phenomenon . This event occurs when the nucleus of a radioactive element emits a beta particle , which causes the breakup of a neutron and causes the change in the number of protons of the element. The change in the number of protons causes the element to change into another type of substance.

Beta decay is a phenomenon that made it possible to prove the existence of neutrinos

By observing the electron emitted during beta decay, it can be seen that it does not have all the energy lost by the nucleus of the radioactive element. As it is known that energy cannot simply be destroyed or lost , some unknown element must carry the missing energy.

In 1930, Austrian physicist Wolfgang Pauli proposed that the spare energy should belong to an uncharged particle. However, the scientist’s assumption was not taken seriously. Later, the Italian Enrico Fermi , who believed in the Pauli hypothesis, called these particles neutrinos , which in Italian means “small neutrons”.

Don’t stop now… There’s more after the publicity 😉

In 1955, Fred Reines and Clyde Cowan , through a process called inverse beta decay , were able to detect neutrinos and, thus, proved the existence of these particles.

Why are these particles important to Science?

After photons, neutrinos are the most abundant particles in the entire universe. Every second, the Sun produces about 60 billion neutrinos per square centimeter. At any given moment, billions of these particles cross an area corresponding to a human fingernail.

The Earth is constantly hit by neutrinos from numerous intra and extragalactic sources. Detecting them to understand their formation and development can lead us to an understanding of the origins of the universe and clarify, for example, fundamental questions about the formation of matter and antimatter in the beginning of everything.

types of neutrinos

The classification of particles is related to their interactions . The strong interaction is responsible for holding the atomic nucleus together. The so-called weak interaction is involved in beta decay. Each type of interaction acts on a certain group of particles. Leptons , for example, are the particles that are under the influence of the weak interaction, and the hadrons suffer the action of the strong interaction.

Electrons, muons and taus are the existing types of leptons. For each type of muon, there is a corresponding neutrino.

Related Articles

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top button