Bosons vs. Fermions


Core Concepts

In this article you will be able to fully comprehend what are bosons and fermions, you will also understand their differences, and their importance to the world of physics nowadays!

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A boson is a kind of particle in particle physics that adheres to the Bose-Einstein statistics laws. The quantum spin of these bosons also has an integer value, such as 0, 1, -1, -2, 3, etc. Bosons are also referred to as force particles because they govern how physical forces like electromagnetic and potentially even gravity itself interact.

Indian physicist Satyendra Nath Bose, who collaborated with Albert Einstein to create the statistical approach known as Bose-Einstein statistics, gave rise to the word boson, derived from his last name. Bose initially suggested the approach in a 1924 study attempting to explain the behavior of photons in order to completely comprehend Planck’s law, which was the thermodynamics equilibrium equation that resulted from Max Planck’s work on the blackbody radiation problem.

Researchers have not yet confirmed the existence of a boson that can convey gravity, although it remains a possibility. Smaller particles make up other bosons, but the gauge bosons are fundamental particles, meaning they do not consist of anything smaller.

Types of Bosons


Either fermions or bosons, with odd half-integer spins, are all observable elementary particles. Elementary bosons have a unique function in particle physics, as opposed to leptons and quarks, which are fermions and make up ordinary matter. They either function as force carriers that generate forces between other particles or, in one instance, as the source of the mass phenomena.

The Standard Model of Particle Physics proposes the existence of five elementary bosons:

One of them is a scalar boson (spin=0)

  1. Higgs boson: The particle that, through the Higgs process, contributes to the phenomenon of mass.

The other four are vector bosons (spin=1)

  1. Photon: The electromagnetic field’s force carrier.
  2. Gluons: Carriers of strong force that mediate it. There are eight varieties.
  3. Neutral weak boson: The force mediator for the weak force.
  4. Charged weak bosons: Additionally weak force mediating force carriers. There are two varieties.


Depending on their component parts, composite particles can either be bosons or fermions. Any composite particle made up of an even number of fermions is a boson since bosons have integer spin while fermions have odd half-integer spin.

Among the composite bosons are:

  • All mesons
  • Stable nuclei of even mass number such as deuterium, helium-4, carbon-12 and lead-208.

Higgs Boson

The Higgs boson, which gives other particles their mass, is the fundamental force-carrying particle of the Higgs field. Peter Higgs, after whom the particle is named, and his associates, initially proposed the theory for this field in the middle of the 1960s. On July 4, 2012, scientists at the Large Hadron Collider (LHC), the world’s most potent particle accelerator, based at the European Particle Physics Laboratory CERN in Switzerland, made the particle’s ultimate discovery. The LHC finalized the standard model of particle physics, the best account we have of the subatomic universe, by confirming the existence of the Higgs field and the process that gives origin to mass.

According to CERN, the Higgs boson is 130 times more heavy than a proton with a mass of 125 billion electron volts. It also has no charge and no spin, making it the quantum mechanical counterpart of angular momentum. The discovery of the Higgs boson, particularly through the popular media, firmly established the nickname “the God Particle.” The Nobel Prize-winning scientist Leon Lederman, who faced exasperation over the challenges in discovering the Higgs boson, frequently attributes the phrase “the God Particle” to it.


A fermion is a category of particle in particle physics that abides by the Pauli Exclusion Principle, one of the Fermi-Dirac statistics laws. These fermions also have a half-integer quantum spin, such as 1/2, -1/2, -3/2, and so on.

Fermions, such as protons, neutrons, and electrons, which make up the majority of what we consider to be physical stuff of our universe, are frequently referred to as matter particles.

The physicist Wolfgang Pauli made the first prediction of fermions in 1925 while attempting to explain Niels Bohr’s postulated atomic structure from 1922. Bohr had developed an atomic model with electron shells that allowed electrons to move in stable orbits around the atomic nucleus using experimental data. Pauli was attempting to provide an explanation for why this structure would be stable, despite the fact that it fit the facts rather well.

Enrico Fermi and Paul Dirac independently sought to comprehend more facets of the seemingly contradictory behavior of electrons in 1926. As a result, they developed a more thorough statistical approach to dealing with electrons. Even though Fermi created the system first, they collaborated sufficiently and both contributed enough work to label their statistical approach as Fermi-Dirac statistics, despite the particles were named after Fermi.

Types of Fermions


The Standard Model recognizes two categories of elementary fermions: quarks and leptons. The model can discriminate between 24 distinct fermions in total. There are six leptons (electron, electron neutrino, muon, muon neutrino, tauon, and tauon neutrino), six quarks (up, down, strange, charm, bottom, and top), and corresponding antiparticles for each of these.

There are several sorts of fermions in mathematics, with the three most prevalent forms being:

  • Weyl fermions
  • Dirac fermions
  • Majorana fermions


A particle that has an odd number of fermions is a fermion in and of itself. Its spin will be a half-integer. Several examples are as follows:

  • Three fermionic quarks are present in a baryon, such as a proton or neutron.
  • A carbon-13 atom’s nucleus is made up of six protons and seven neutrons.
  • Three particles make up the helium-3 atom: two protons, one neutron, and two electrons. One proton, one neutron, and one electron make up the deuterium atom.

One can only observe the bosonic or fermionic activity of a composite particle’s (or system’s) at distances that are significantly greater than the system’s size. A composite particle (or system) operates in accordance with the composition of its constituent parts at proximity, where spatial structure starts to matter. When fermions are loosely coupled in pairs, they can behave in a bosonic manner.

Bosons vs. Fermions Practice Problems

Problem 1

Identify the particle type
Label the following particles as either “Boson” or “Fermion”:
a) Photon
b) Proton
c) Electron
d) Neutron

Problem 2

Can bosons have half-integer spins? Can fermions have integer spins?

Problem 3

A deuteron is a nucleus composed of a proton and a neutron, bound together. Determine whether the deuteron is a boson or a fermion.

Problem 4

Explain why bosons are more likely to clump together while fermions tend to keep apart.

Problem 5

State whether the following particles have “Integer” or “Half-Integer” spin:
a) Photon
b) Proton
c) Electron
d) Neutron

Bosons vs. Fermions Practice Problems Solutions

Answer 1

a) Photon- Boson
b) Proton- Fermion
c) Electron- Fermion
d) Neutron- Fermion

Answer 2

Bosons: Integer or zero spin
Fermions: Half-integer spin

Bosons cannot have half-integer spins because they obey Bose-Einstein statistics, which allow multiple particles to occupy the same quantum state. On the other hand, fermions cannot have integer spins due to the Pauli Exclusion Principle, which forbids two identical fermions from occupying the same state.

Answer 3

The deuteron is a boson. Even though protons and neutrons are fermions, when they form a deuteron, they combine to create a bosonic composite particle. This is because the total spin of the deuteron is an integer value (spin-1), which follows the rules for bosons.

Answer 4

Bosons are more likely to clump together because they can occupy the same quantum state simultaneously, following Bose-Einstein statistics. As a result, they tend to condense into the same low-energy state, creating macroscopic quantum phenomena like Bose-Einstein condensates. Fermions, however, obey the Pauli Exclusion Principle, which prohibits them from occupying the same quantum state, leading to the “exclusion” effect and keeping them apart.

Answer 5

a) Photon- integrer or zero spin
b) Proton- half integer spin
c) Electron- half integer spin
d) Neutron- half integer spin

Further Reading

If you are interested on the topic, we recommend you to read this article!