What is Fundamental particles: Definition and 25 Discussions

In particle physics, an elementary particle or fundamental particle is a subatomic particle with no (currently known) substructure, i.e. it is not composed of other particles. Particles currently thought to be elementary include the fundamental fermions (quarks, leptons, antiquarks, and antileptons), which generally are "matter particles" and "antimatter particles", as well as the fundamental bosons (gauge bosons and the Higgs boson), which generally are "force particles" that mediate interactions among fermions. A particle containing two or more elementary particles is called a composite particle.
Ordinary matter is composed of atoms, once presumed to be elementary particles—atomos meaning "unable to be cut" in Greek—although the atom's existence remained controversial until about 1905, as some leading physicists regarded molecules as mathematical illusions, and matter as ultimately composed of energy. Subatomic constituents of the atom were first identified in the early 1930s; the electron and the proton, along with the photon, the particle of electromagnetic radiation. At that time, the recent advent of quantum mechanics was radically altering the conception of particles, as a single particle could seemingly span a field as would a wave, a paradox still eluding satisfactory explanation.Via quantum theory, protons and neutrons were found to contain quarks – up quarks and down quarks – now considered elementary particles. And within a molecule, the electron's three degrees of freedom (charge, spin, orbital) can separate via the wavefunction into three quasiparticles (holon, spinon, and orbiton). Yet a free electron – one which is not orbiting an atomic nucleus and hence lacks orbital motion – appears unsplittable and remains regarded as an elementary particle.Around 1980, an elementary particle's status as indeed elementary – an ultimate constituent of substance – was mostly discarded for a more practical outlook, embodied in particle physics' Standard Model, what's known as science's most experimentally successful theory. Many elaborations upon and theories beyond the Standard Model, including the popular supersymmetry, double the number of elementary particles by hypothesizing that each known particle associates with a "shadow" partner far more massive, although all such superpartners remain undiscovered. Meanwhile, an elementary boson mediating gravitation – the graviton – remains hypothetical. Also, as hypotheses indicate, spacetime is probably quantized, so there most likely exist "atoms" of space and time themselves.

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  1. A

    B Fundamental particles and mass quantization

    We know that the energy levels for electrons surrounding nucleus are quantized , only coming in discrete levels. When I see the standard model of elementary particles table I notice specific masses for each of the particles whether they be quarks or leptons or bosons like the higgs. I know that...
  2. G

    B F = dP/dt on subatomic particles

    I am trying to code a simulator for fundamental particles. The problem is that on a subatomic level, force works differently than on a macroscopic level. Then there is also the problem of Heisenberg's Uncertainty Principle. How is a force applied to a subatomic particle? I did some research and...
  3. ohwilleke

    I Excited hadrons v. fundamental particles

    Mesons and baryons have both a ground state and excited states involving the same valence quarks but a higher mass (which can in principle be calculated from QCD). Fundamental fermions and bosons, however, do not appear to display this behavior. They have a ground state, and while there are...
  4. S

    B Electromagnetic fields of fundamental particles -- help please

    Hi, we know that the particles have intrinsic properties for them electric field and magnetic moment, but for what I mean particles, I mean quarks, the fundamental blocks of (protons, neutrons and mesons) with everything that nobody explained as electric and The magnetic field of a particle and...
  5. A

    B No new fundamental particles at CERN until today

    I remember reading in some book, that the most important experiments are those that produce negative results: the Michelson-Morley experiment for example. The standard model is complete after the Higgs boson. I believe that if no new particle appears in CERN, it would be one of the greatest...
  6. Nathan Warford

    I Theoretical Models for Sizes of Fundamental Particles

    I am aware that according to the Standard Model of Particle Physics, fundamental particles such as electrons and quarks are treated as point-like particles. However, if fundamental particles are indeed 0-dimentional points with no spatial extent, it creates problems (i.e. fundamental particles...
  7. N

    Fundamental point like particles?

    Is it possible that fundamental point like particles (ie electrons) are actually particles with shape size and structure that are too small for any of our current technology to detect?
  8. J

    Why are fundamental particles round?

    why is each fundamental particle round
  9. H

    Why are quarks fundamental particles?

    Are quarks really considered fundamental particles that cannot be divided further? If an up quark can transmute to a down quark and release a W+ boson which decays to a positron and a neutrino (for example) - doesn't this mean that there is substructure to a quark? What exactly is it that makes...
  10. I

    If electrons are fundamental particles then why do they -

    If electrons are fundamental particles and leptons then what happens when they emit or absorb photons or Z particles? What is known about the mechanism of these aborptions or emissions for any particles? Do the absorbed electrons gain mass as particles are described to do as they move nearer to...
  11. O

    Do Fundamental Particles Experience Heat?

    Heat is a product of excited energy states of the fundamental particles that make up atoms, correct? So do the particles, themselves, get "hot" - or is heat just experienced as radiation on the macroscopic scale? Do neutrons, for example, have a thermal property at all?
  12. S

    Photon vs other fundamental particles - decoherence

    1. What (property) makes a photon less likely to decohere/(entangle with the environment) relative to other "fundamental" particles (non leptons?) such as an electron?...say during single particle interference experiment Photon single particle interference can done without the need for a...
  13. TrickyDicky

    Fundamental particles in physics

    I was reading this recent Scientific american article which I found interesting, and was spurred on by it to ask a couple of questions. Is the mathematical concept of fundamental point particle currently a basic postulate in physics(let's take as current physics the QM based-QFT modern...
  14. G

    Graphic Design & Science: Fundamental Particles Visualation

    Graphic Design & Science: Fundamental Particles Visualisation Hello my name is Brendon. I'm a graphic designer interested in science communication and currently studying a masters in graphic design. I was wondering if anybody would be able to help me with a few queries with regards to...
  15. M

    Fundamental Particles - Meson Decay Question

    Homework Statement The pion-zero meson has its mass quoted as 135.0MeV/c2. It decays into two gamma rays: ∏0 → γ + γ b) Assuming the ∏0meson to be initially at rest, calculate the energy and hence the wavelength of the two gamma rays. Homework Equations E= hc/λ The Attempt at a...
  16. V

    True or false? Fundamental particles

    True or false? 1. It is not possible to prove the point of origin of a photon 2. It is not possible to prove the point of origin of a free electron 3. It is not possible to prove that protons or neutrons exist inside a nucleus Can someone please confirm?
  17. R

    How much of a hydrogen atom's mass is due to the mass of fundamental particles?

    If one were to subtract the kinetic energies of all fundamental particles within hydrogen, as well as all of the potential energy of all bound states between these particles, how much mass (as a percentage of the total) would remain? Ignore the kinetic energy due to the hydrogen's speed.And...
  18. K

    What's the difference between fundamental particles and composite particles?

    I'm confused, by composite particle we probably mean when we use something to smash it, something new will come up, right? Then what's so different about fundamental particles? For example if we "smash" a electron with a positron, we also get something new--photon. I guess I am making some...
  19. J

    Masses of fundamental particles

    How were the masses of fundamental particles(electrons,protons,neutrons) determined?
  20. O

    Problems with fundamental particles and quarks

    Problems with fundamental particles and quarks :( Hi, I have no idea where to post this so I hope its ok... I'm studying A level physics. We have a topic on fundamental particles. Yea couple of questions... 1. Whats the difference between a (insert lepton here)-neutrino, and its...
  21. L

    What is charge? Why do fundamental particles possess it?

    I attended a colloquium a few days ago concerning the LHC and the search for the Higgs Boson. After some thought, I have the following question. Among other things, there are two measurable properties of all of the fundamental particles in the Standard Model: mass and charge. It is...
  22. Loren Booda

    Are all fundamental particles singular?

    Is there a fundamental particle (like a Planck black hole) that has a finite radius?
  23. M

    Quantum numbers of fundamental particles?

    Which are (basic?) quantum nubers of fundamental particles? I am having problems becouse a lot of expresions are used on sites on the web: el. charge, color charge, mass, taste, spin, barion & lepton number... to many :eek: :confused:
  24. P

    Fundamental Particles: Definition & Properties

    Perhaps this question has been addressed before, but, allow me to ask: What consitutes the classification of a "fundamental" particle? Does a fundamental particle have ANY half-life? Seems it would not. Is a fundamental particle completely impervious to destruction?
  25. R

    String resonances and fundamental particles

    Does anyone know of any good references on the relationship between string vibrations and fundamental particles such as quarks, leptons, and the gauge bosons, containing an explicit mathematical description of said relationship? Any information would be appreciated.