| Dictionary, Encyclopedia and Thesaurus - The Free Dictionary 1,753,483,298 visitors served. |
|
Dictionary/ thesaurus | Medical dictionary | Legal dictionary | Financial dictionary | Acronyms | Idioms | Encyclopedia | Wikipedia encyclopedia | ? |
helicity |
Also found in: Dictionary/thesaurus, Wikipedia | 0.02 sec. |
|
helicity [he′lis·əd·ē] (quantum mechanics) The component of the spin of a particle along its momentum. Helicity (quantum mechanics) A fundamental quantized variable used in quantum mechanics to specify the relative orientations of spin and linear momentum of massless particles. It is a requirement of fundamental Dirac quantum mechanics that such particles have their spins aligned either parallel or antiparallel to their linear momentum. Particles having parallel alignment are arbitrarily assigned helicity +1; those having antiparallel alignment, -1. See Momentum, Spin (quantum mechanics) In a classic experiment on K electron capture by 152Eu, M. Goldhaber, L. Grodzins, and A. Sunyar first showed that the neutrino emitted in the weak nuclear interaction had negative helicity—that its spin was aligned antiparallel to its momentum. An equivalent description of this situation is that these neutrinos are left-handed. Symmetry requires that antineutrinos be right-handed and have positive helicity. See Electron capture, Elementary particle, Neutrino, Quantum mechanics, Symmetry laws (physics) How to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit webmaster's page for free fun content. |
|
| ? Mentioned in | ? References in periodicals archive | |
|---|---|---|
However the violation of parity equires that the photons be emitted as an incoherent mixture of El and Ml radiations and therefore the radiation is left circularly polarized and the transfer of helicity from electron to photon approaches 100% at the end-point of the spectrum. I was hoping that when we saw the crystal structure of the needles, we would see a lock-and-key phenomenon" accounting for the helicity of the aggregate, Fuchs says. Storm-Relative Helicity (SRH) is defined for a layer of depth h as (Davies-Jones et al. |
| Encyclopedia |
| Free Tools: |
For surfers:
Free toolbar & extensions |
Word of the Day |
Help
For webmasters: Free content | Linking | Lookup box | Double-click lookup | Partner with us |
|---|