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arXiv · 1508.02188

Helicity of spin-extended chiral particles

M. Elbistan·C. Duval·P. A. Horvathy·P. -M. Zhang
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Abstract

The helicity of a free massless relativistic particle, $χ^o={\bf s}.{\bf p}/|{\bf p}|$, is generalized, for a particle in an electromagnetic field, to $χ={\bf s}.{\bf p}/{\cal E}$, where ${\cal E}$ is the modified kinetic energy. Both $χ^o$ and $χ$ coincide and are conserved for minimal coupling (gyromagnetic ratio $g=0$) but are different and neither of them is conserved when the coupling is non-minimal, $g\neq0$, generating non-zero effective mass. For a chiral particle with $g=2$ in a constant electric field both helicities converge asymptotically to the same value. Helicity is also conserved for minimal gravitational coupling.

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M. Elbistan, C. Duval, P. A. Horvathy, P. -M. Zhang. 2016-04-04. Helicity of spin-extended chiral particles. https://doi.org/10.1016/j.physleta.2016.03.016

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