Neutrino and antineutrino are two subatomic particles. The key difference between antineutrino and neutrino is that the neutrino is a particle whereas the antineutrino is an antiparticle.
There are many usages of neutrino and antineutrino in various fields. We can use the properties such as mass, charge, and spin of these particles in many ways to detect and determine properties of systems. We can define a neutrino as a subatomic particle having no electrical charge (but other properties are similar to an electron), very little mass and it is very abundant in universe. On the other hand, an antineutrino is the anti-particle of neutrino.
CONTENTS
1. Overview and Key Difference
2. What is Antineutrino
3. What is Neutrino
4. Side by Side Comparison – Antineutrino vs Neutrino in Tabular Form
5. Summary
What is Antineutrino?
To understand what an antineutrino is, one must first understand what antiparticles are. Most of the particles we know have antiparticles. An antiparticle is a particle having the same mass, but the opposite charge to a certain particle. However, the charge is not the only difference between particles and antiparticles. If a particle and an antiparticle contacts, they will annihilate to produce energy. For the annihilation to occur, both the particle and the antiparticle must exist in the appropriate quantum states.
Figure 01: Formation of an Antineutrino from Beta Decay
Moreover, an antineutrino is the antiparticle of the neutrino. Since neutrino has no charge, some people propose that neutrino and antineutrino are the same particles. Particle-antiparticle pairs having this property (a particle having its own antiparticle with same properties) are known as Majorana particles. Like the neutrino, antineutron also has a spin of ½. Also, antineutrinos interact through weak forces and gravitational forces only. Therefore, the detection of antineutrons is hard. This particle is a lepton. This means antineutrino is an elementary particle of half-integer spin (spin 1 ⁄ 2 ) that does not undergo strong interactions.
What is Neutrino?
The neutrino means “small neutral one”. We can denote it by the Greek letter ν (nu). The neutrino is an elementary subatomic particle, which has very weak interactions with matter; which means, it can pass through matter without making many interactions such as collisions and diversions. Neutrino is electrically neutral.
The mass of this particle is very small but not zero. This small amount of mass and the electrical neutrality are the reasons the neutrino has very little or almost no interactions with matter. They are created due to certain types of nuclear decays or nuclear reactions. The nuclear fusion inside the sun, nuclear fission inside atomic reactors and cosmic ray collisions with atoms are some of the reasons for the creation of these particles.
Figure 02: Symbol of Muon Neutrino
There are three types of neutrons namely electron neutrons, tau neutrons, and muon neutrons. These are known as flavours of neutrinos in particle physics. The first evidence of the neutrino was that the conservation of mass, energy and momentum were not present in nuclear decay equations.
In 1930, Wolfgang Pauli proposed that there should be a particle with a very little amount of mass and no charge in order to balance the conservation laws. Then, the detection of the first neutrons happened in 1956, and the main source of neutrinos in the earth is the sun. Approximately 65 billion solar neutrinos pass through every square centimetre. Moreover, the theory of neutrino oscillations suggests that the neutrinos change flavours or “oscillates” between flavours. Neutrino has a spin of ½. A particle having half-integer spin falls into the lepton family.
What is the Difference Between Antineutrino and Neutrino?
Both neutrino and antineutrino are two subatomic particles. However, the key difference between antineutrino and neutrino is that the neutrino is a particle whereas the antineutrino is an antiparticle. Moreover, a neutrino-antineutrino collision will annihilate both particles and produce two photons.
Summary – Antineutrino vs Neutrino
Both neutrino and antineutrino are two subatomic particles. The key difference between antineutrino and neutrino is that neutrino is a particle whereas antineutrino is an antiparticle.
Reference:
1. Britannica, The Editors of Encyclopaedia. “Neutrino.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 26 July 2018. Available here
Image Courtesy:
1.”27735417341″ by Kanijoman (CC BY 2.0) via Flickr
2.”Muon neutrino”By MissMJ (CC BY 3.0) via Commons Wikimedia
Great, although it didn’t specify the difference of the neutrino and the anti-neutrino, just the anihilation when the two of them colides.
How do they know which is which?