Antimatter may sound like something out of a science fiction novel, but it exists in the same way that you do. Protons, electrons, and neutrons are the building blocks of matter, each with their own mass and charge (either positive, negative, or neutral). Antimatter particles resemble their matter counterparts in appearance: they have the same mass but opposing charges.

The electron, for example, has a negative electric charge, but the positron (antielectron) has a positive charge. A negatively charged proton is known as an antiproton. Antimatter particles like antiprotons and positrons can combine to produce antiatoms in the same manner as protons and electrons combine to make atoms. However, matter rather than antimatter makes up the majority of what we observe in the cosmos. Scientists don’t know where all of the antimatter is, but they’re hoping that research like the Deep Underground Neutrino Experiment will help them figure it out soon. Antiatoms can also be created and studied in a laboratory, however this is extremely difficult. When matter and antimatter collide, they obliterate each other in a flash of light.

As a result, an antineutrino is essentially a neutrino’s “opposite version.” But, if charge is one of the primary differences between matter and antimatter, what does it mean if neutrinos are neutral? Does this imply that neutrinos and antineutrinos are the same thing, with the exception of the particles they make (positrons or electrons)? Scientists are undecided. Many experiments are being conducted or proposed to see if this is the case.

Scientists consider the three neutrinos (electron, muon, and tau neutrinos) and the three antineutrinos (electron, muon, and tau antineutrinos) to be separate particles for the time being.


Antineutrinos pique the curiosity of scientists for both practical and theoretical reasons. Antineutrinos are created in large quantities in nuclear reactors, and these antineutrinos can be utilized to monitor the reactor core precisely. Scientists, on the other hand, wish to investigate antineutrino oscillations to see if neutrinos and their antimatter counterparts behave in unexpectedly different ways.

The antineutrino is the neutrino’s antiparticle partner, meaning that the antineutrino has the same mass as the neutrino but the opposite “charge.” Despite the fact that neutrinos are electromagnetically neutral (they have no electric charge or magnetic moment), they can carry a different form of charge: the lepton number. These are distinguishing characteristics that can tell a particle apart from an antiparticle (along with properties such as helicity).

The three families of leptons are assigned family lepton numbers, which are easily recalled by their flavors. One set consists of the electron and electron neutrino (and their antiparticles), another of the muon and muon neutrino, and the third of the tau and tau neutrino. Electrons and electron neutrinos have a value of 1, positrons and electron antineutrinos have a value of -1, while all other leptons (associated with muons or taus) have a value of 0 because they have no electron flavor. The same thing happens when muons and muon neutrinos have a muon number of 1, their antiparticles have a muon number of -1, and everything else has a muon number of 0. The tau and tau neutrino should be treated in the same way!

If the summed family lepton flavor numbers before and after a reaction stay unchanged, scientists consider the overall lepton number to be conserved. It’s a way of balancing the equations that describe reactions, and it’s an excellent predictor of whether or not a given process will occur. So far, no violation of total lepton number conservation has been observed: the weak interaction consistently produces the right numbers and types of neutrinos and antineutrinos. The lepton number, on the other hand, would not be conserved if neutrinos and antineutrinos are the same particle. It’s possible that Neutrinos hasn’t told the whole tale yet.

The fact that neutrinos oscillate between flavors indicates that the flavor of the family lepton is not conserved. If neutrinos and antineutrinos, for example, fluctuate from one flavor to another at different rates, the so-called charge-parity (CP) symmetry would be broken. This would be very intriguing because CP symmetry violation is a prerequisite for transitioning from a “neutral” universe (equal parts matter and antimatter) to the matter-dominated universe we live in. This is still one of the most difficult problems for particle physicists to solve.