In particle physics, a massless particle is an elementary particle whose invariant mass is zero. At present the only confirmed massless particle is the...

Higgs mechanism, a way for some particles to acquire mass. All fundamental particles known at the time should be massless at very high energies, but fully...

is much smaller than that of the other known elementary particles (excluding massless particles). The weak force has a very short range, the gravitational...

direction) have zero invariant mass and are referred to as massless. A physical object or particle moving faster than the speed of light would have space-like...

electromagnetism. Massless particles and field perturbations, such as gravitational waves, also travel at speed c in vacuum. Such particles and waves travel...

This result suggests that, if a massless spin-2 particle is discovered, it must be the graviton. Many hypothetical particle candidates for dark matter have...

In the physical sciences, a particle (or corpuscle in older texts) is a small localized object which can be described by several physical or chemical properties...

a massive particle, By evaluating the norm of the four-momentum of the system. This method applies to both massive and massless particles, and can be...

relativistic particles. These two types of relativistic particles are remarked as massless and massive, respectively. In experiments, massive particles are relativistic...

The spin of a particle may be used to define a handedness, or helicity, for that particle, which, in the case of a massless particle, is the same as...

physics, a subatomic particle is a particle smaller than an atom. According to the Standard Model of particle physics, a subatomic particle can be either a...

including dark matter), mostly photons and other massless force carriers. The Standard Model of particle physics contains 12 flavors of elementary fermions...

massive particle refers to a massful particle which has real non-zero rest mass (such as baryonic matter), the counter-part to the term massless particle. According...

discrete. For a massive particle of spin S, the eigenvalues of helicity are S, S − 1, S − 2, ..., −S.: 12  For massless particles, not all of spin eigenvalues...

In particle physics, a boson (/ˈboʊzɒn/ /ˈboʊsɒn/) is a subatomic particle whose spin quantum number has an integer value (0, 1, 2, ...). Bosons form...

particle to exist tends to be canceled out by destructive interference over longer distances and times. As a consequence, a real photon is massless and...

oscillations Massive particle – bradyon, aka tardyon Massless particle – luxon Retrocausality Tachyonic antitelephone Virtual particle Wheeler–Feynman absorber...

_{\text{th}}={\sqrt {\frac {2\pi \hbar ^{2}}{mk_{\text{B}}T}}}.} For massless (or highly relativistic) particles, the thermal wavelength is defined as λ th = h c 2 π...

such as the scalar or vector mesons. If their current quarks were massless particles, it could make the chiral symmetry exact and thus the Goldstone theorem...

Photons are massless particles that can move no faster than the speed of light measured in vacuum. The photon belongs to the class of boson particles. As with...

matter, independent of velocity. Massless particles such as photons have zero invariant mass, but massless free particles have both momentum and energy....

gravitational interactions do. This result suggests that, if a massless spin-2 particle is discovered, it must be the graviton. It is hypothesized that...

be given in this article. For both massive and massless particles in a box, the states of a particle are enumerated by a set of quantum numbers [nx,...

new massless (or light, if the symmetry is not exact) scalar particles appear in the spectrum of possible excitations. There is one scalar particle—called...

equivalent E = p 2 2 m {\textstyle E={\frac {p^{2}}{2m}}} ). if the particle is a massless particle: ω = k c {\displaystyle \omega =kc} . The eigenvalue spectrum...

traveled by massive particles), and is usually taken to be equal to it. For lightlike (or null) orbits (which are traveled by massless particles such as the photon)...

GLOO-on) is a type of massless elementary particle that mediates the strong interaction between quarks, acting as the exchange particle for the interaction...

Z bosons have mass while photons are massless was a major obstacle in developing electroweak theory. These particles are accurately described by an SU(2)...

In particle physics, a fermion is a subatomic particle that follows Fermi–Dirac statistics. Fermions have a half-integer spin (spin ⁠1/2⁠, spin ⁠3/2⁠...

responsible for interactions between electrically charged particles. The photon is massless and is described by the theory of quantum electrodynamics...