Elementary Particles

leptons
quarks
gauge bosons
νe
νμ
ντ
νe
νμ
ντ
e
μ
τ
e+
μ
τ
u
c
t
u
c
t
d
s
b
d
s
b
γ
W
W+
Z
g
H0
G
mass
spin
charge
electronic number
muonic number
tauonic number
baryon number
isospin
strangeness
charm
bottomness
topness
particles
antiparticles
fermions
bosons
elementary particles
elementary particles are the most fundamental constituents of the universe; they are not, as far as we know, made up of other particles; the proton, for example, is not an elementary particle, because it is made up of three quarks, whereas the electron is an elementary particle, because it appears to have no internal structure

Notes

This representation of 31 elementary particles shows what things are really made of

These 31 elementary particles are the most fundamental constituents of the universe. They are not, as far as we know, made up of other particles. The proton, for example, is not an elementary particle, because it is made up of three quarks, whereas the electron is an elementary particle, because it seems to have no internal structure.

31 seems a lot of elementary particles, but most of what we think of as matter consists of just 3 of them: the up quark, the down quark and the electron (protons and neutrons are both made of up and down quarks; atoms are made of protons, neutrons and electrons; most of what we think of as matter is made of atoms). We should remember, however, that much of the mass of atoms is due to the gluons that bind the quarks; nor should we forget about the photons that bind the electrons to the quarks.

2 of the elementary particles are speculative. No-one has ever observed a Higgs boson or a graviton. They have both been dreamt up by physicists in an attempt to explain mass and the gravitational force.

Where do these 31 elementary particles come from? Why 31? Why these 31, rather than some other 31? Nobody knows.

Every inch of this visualization is active. Move your mouse over a particle to show its name, classification, properties and further information. Move your mouse over a category to show which particles belong to that category. Or move your mouse over a property to show the value of that property for each of the particles. Click on a control to hold it down, then click elsewhere to release it.

Comments

Bernhardt B. Husen ⋅ 19 April 2013

You write: "This representation of 31 elementary particles shows what things are really made of" ...emphasizing "really".... you forget to emphasize that this is what you REALLY believe !! Because it is not sure at all that the standard model is "watertight"... I guess this comment is very "impolite or inappropriate" in your optic...

Mark Jeffery ⋅ 19 April 2013

That's neither impolite nor inappropriate, it's a great point, Bernhardt. You're right, the Standard Model is, well, just a model; and even if we could be certain that its predictions were correct, would we really then know what things are made of, or would we have no more than a bunch of equations? That's where physics meets philosophy…

James Robert Johnson ⋅ 14 May 2013

I do appreciate this page. It condenses a difficult subject down to where I can almost begin to understand it. Thank you.

More

This is one of a series of visualizations of what things are made of, from elementary particles to organic molecules…

Elementary Particles – this page

Mesons

Baryons

Nuclides

Atoms

…check back soon for the next in the series

More physics made thinkable

More science made thinkable

More Universe made thinkable

Latest things made thinkable

Text

A text summary of this presentation is shown below for easy reference

Particles

electron neutrino   νe

muon neutrino   νμ

tau neutrino   ντ

electron antineutrino   νe

muon antineutrino   νμ

tau antineutrino   ντ

electron   e

electrons are among the most common particles in our world, giving atoms their chemical properties

muon   μ

tau   τ

positron   e+

positrons are antielectrons

antimuon   μ

antitau   τ

up quark   u

up quarks and down quarks are the constituents of neutrons and protons, which make up most of the mass in atoms; this means that most of the matter in our world consists of up quarks, down quarks and the gluons that bind them

charm quark   c

top quark   t

up antiquark   u

charm antiquark   c

top antiquark   t

down quark   d

up quarks and down quarks are the constituents of neutrons and protons, which make up most of the mass in atoms; this means that most of the matter in our world consists of up quarks, down quarks and the gluons that bind them

strange quark   s

bottom quark   b

down antiquark   d

strange antiquark   s

bottom antiquark   b

photon   γ

photons are particles of light (not just infra-red, ultra-violet and visible light, but radio waves, microwaves, x-rays and gamma rays too); photons mediate the electromagnetic force, which holds electrons in atoms

W boson   W

W and Z bosons mediate the weak nuclear force, which is involved in radioactive decay

anti-W boson   W+

W and Z bosons mediate the weak nuclear force, which is involved in radioactive decay

Z boson   Z

W and Z bosons mediate the weak nuclear force, which is involved in radioactive decay

gluon   g

gluons mediate the strong nuclear force, which holds quarks in protons and neutrons, and holds protons and neutrons in atomic nuclei

Higgs boson   H0

Higgs bosons had never been observed prior to 14 March 2013, when evidence for one was found in data from the Large Hadron Collider; physicists hypothesize that Higgs bosons are responsible for the masses of other particles

graviton   G

gravitons have never been observed, but physicists hypothesize that they mediate the gravitational force, which holds planets in orbit around stars

Categories

particles

almost all the matter in our world consists of particles rather than antiparticles; atoms, for example, consist of up quarks, down quarks and electrons rather than up antiquarks, down antiquarks and positrons

antiparticles

antiparticles are the same as particles, except that they seem to be going backwards through time; every particle has an antiparticle with the same mass and spin but otherwise opposite properties; the exceptions are the photon, Z boson, gluon, Higgs boson and graviton, each of which is its own antiparticle

fermions

fermions are particles with half-integer spin, i.e. spin 1/2, 3/2, etc.; fermions are subject to the exclusion principle, which means that there is a limit to the number of fermions you can squeeze into a small space; because electrons are fermions, this gives rise to all the peculiar chemical properties of atoms

bosons

bosons are particles with integer spin, i.e. spin 0, 1, 2, etc.; bosons are not subject to the exclusion principle, which means that there is no limit to the number of bosons you can squeeze into a small space; this allows gauge bosons to mediate the fundamental forces of nature

elementary particles

elementary particles are the most fundamental constituents of the universe; they are not, as far as we know, made up of other particles; the proton, for example, is not an elementary particle, because it is made up of three quarks, whereas the electron is an elementary particle, because it appears to have no internal structure

leptons

leptons are particles that do not interact strongly with other particles; electrons (along with two heavier but otherwise identical particles called the muon and the tau) are charged, so interact electromagnetically, while neutrinos are uncharged, so interact only weakly (they pass right through the Earth)

quarks

quarks are particles that interact strongly with each other; they have never been observed alone, always bound in twos and threes to form composite particles called hadrons, such as the protons and neutrons from which atomic nuclei are made

gauge bosons

gauge bosons are particles that mediate the fundamental forces of nature (photons the electromagnetic force, W and Z bosons the weak nuclear force, and gluons the strong nuclear force); Higgs bosons had never been observed prior to 14 March 2013, but are thought to be responsible for the masses of other particles; gravitons, hypothesized to explain the gravitational force, have still never been observed

Date

First published 23 February 2011

other pages on things made thinkable

1   1   1
If Patents Were Abolished…   Baryons   Antarctic Exploration Timeline