Keywords: Right left helicity.svg en It's convenient to quantize the spin of spin-1/2 particles along their direction of motion When the spin and the momentum are parallel the particle is called right-handed; when they are antiparallel the particle is left-handed These are known as helicity states Red arrows represent the spin; green arrows are the momentum en Image Right left helicity jpg en User;HEL User Stannered 2007-02-21 2008-06-11 HEL Other versions Right left helicity zh svg Other fields + Spin intrinsic angular momentum |