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Spin of elementary particles

Spin of elementary particles #Physics #Spin #Ballet Elementary particles generally have an intrinsic angular momentum that corresponds to their rotation, and this is called spin. For elementary particles with finite mass, there always exists a rest frame, so the angular momentum of the elementary particle in that system becomes its intrinsic angular momentum. In quantum mechanics, the magnitude of angular momentum is limited to integer multiples or half of the Planck constant. There are a total of 2S+1 independent states of spin S. For example, an electron has a spin of 1/2 and has two independent states. The situation is different for particles with zero mass since there is no rest frame. A particle that has no mass and is moving at the speed of light can be characterized by the amount of angular momentum (helicity) in its momentum direction. The value of helicity does not change no matter what Lorentz transformation is performed, so when the mass is zero, the particles can be classified by helicity rather than spin. Like spin, the value of helicity can be 0, 1/2, 1... Video by Pavel Danilyuk Prelude No. 2 by Chris Zabriskie is licensed under a Creative Commons Attribution 4.0 license. https://creativecommons.org/licenses/... Source: http://chriszabriskie.com/preludes/ Artist: http://chriszabriskie.com/