@article{Two and three particles entanglement; helicity and spin with momentum_2023, volume={11}, url={https://oiccpress.com/journal-of-theoretical-and-applied-physics/article/two-and-three-particles-entanglement-helicity-and-spin-with-momentum/}, DOI={10.1007/s40094-017-0265-9}, abstractNote={AbstractConstruction of the reduced spin and helicity density matrix for systems of two and three particles are described by a wave packet with sharp and Gaussian momentum distribution. The entropy for the spin and helicity part of the systems is calculated from the viewpoint of moving observers.}, number={4}, journal={Journal of Theoretical and Applied Physics}, publisher={OICC Press}, year={2023}, month={Nov.}, keywords={Helicity, Spin, Entanglement, Entropy} }