The fundamental subatomic particles that have no (currently known) substructure. These include fermions (quarks, leptons, antiquarks, and antileptons) and bosons (gauge bosons and the Higgs boson). A particle containing two or more elementary particles is a composite particle.
Questions tagged [elementary-particles]
503 questions
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Do electrons have shape?
According to the Wikipedia page on the electron:
The electron has no known substructure. Hence, it is defined or assumed to be a point particle with a point charge and no spatial extent.
Does point particle mean the particle should not have a…
Anil Bharadia
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Do photons truly exist in a physical sense or are they just a useful concept like $i = \sqrt{-1}$?
Reading about photons I hear different explanations like "elementary particle", "probability cloud", "energy quanta" and so forth. Since probably no one has ever seen a photon (if "seen" it supposedly - and rather conveniently - ceases to exist) but…
Jens
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What is the evidence for 'billions of neutrinos pass through your body every second'?
This statement is repeated so often that it has become somewhat of a cliche: 'billions of neutrinos pass through your body every second'. For example see 1, 2, 3, 4, 5, 6.
What is the evidence for it, especially considering that we have never…
Ritesh Singh
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Why are muons considered to be elementary particles in the Standard Model?
According to this article, a muon decays into one electron and two neutrinos.
According to this article, elementary particles or fundamental particles are particles "whose substructure is unknown, thus it is unknown whether it is composed of other…
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Is the graviton hypothetical?
Wikipedia lists the graviton as a hypothetical particle. I wonder whether graviton is indeed hypothetical or does its existence directly follow from modern physics? Does observation of gravitational waves amount to the discovery of graviton or could…
Anixx
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Is the Higgs boson an elementary particle? If so, why does it decay?
The Higgs boson is an excitation of the Higgs field and is very massive and short lived. It also interacts with the Higgs field and thus is able to experience mass.
Why does it decay if it is supposed to be an elementary particle according to the…
user6760
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How can the unstable particles of the standard model be considered particles in their own right if they immediately decay into stable particles?
How can the unstable particles of the standard model be considered particles in their own right if they immediately decay into stable particles?
It would appear to a layman such as myself that these heavier unstable particles are just transient…
Justin
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Where is the evidence that the electron is pointlike?
I'm writing a piece about the electron, and I'm having trouble finding evidence to back up the claim that the evidence is pointlike.
People tend to say the observation of a single electron in a Penning trap shows the upper limit of the particle's…
John Duffield
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Are elementary particles actually more elementary than quasiparticles?
Quarks and leptons are considered elementary particles, while phonons, holes, and solitons are quasiparticles.
In light of emergent phenomena, such as fractionally charged particles in fractional quantum Hall effect and spinon and chargon in…
leongz
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Is there anything in the universe that cannot be compressed?
I've always thought that there is nothing in the universe that cannot be compressed or deformed under enough force but my friend insists that elementary particles are exempt from this.
My thought is that if two such objects collided, since there is…
jeremy south
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Why doesn't an electron rip itself apart?
A proton is stable because of the strong force between quarks, which is not there in electron. So what's the reason for electron's stability?
Abdur Rahim
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Are protons bigger than electrons?
In every text/ physics book that I've read, Protons are mentioned as particles that are bigger, way bigger 2000 times to be precise, than electrons...I believed that until a few minutes ago when I googled "what is the radius of an electron" and then…
alienare 4422
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Is there a reason, other than mass hierarchy, that we associate each quark generation with a particular lepton generation?
The Standard Model contains three generations of quarks, and three generations of leptons. We generally pair off these generations into the "light" generation ($e, \nu_e, u, d$), the "medium" generation ($\mu, \nu_\mu, c, s$), and the "heavy"…
Michael Seifert
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6 answers
Can you split a photon?
I was wondering if a photon is divisible.
If you look at a photon as a particle, then you may be able to split it (in theory).
Is it possible and how do you split it?
Stephan Schielke
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Why are all force particles bosons?
All of the force-particles in the standard model are bosons, now my question is pretty short, namely:
Why are all force particles bosons?
This can't be a coincidence.
Nick
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