Helizitäten

Helizitäten is a term used in physics, particularly in quantum mechanics and particle physics, to describe a specific property of a particle related to its spin and its direction of motion. It is closely related to the concept of chirality but is a more precise measurement in relativistic contexts. Essentially, helizität is the projection of a particle's spin vector onto its momentum vector.

The helizität of a particle can be either positive or negative. A positive helizität means the spin is aligned in the same direction as the momentum, while a negative helizität indicates the spin is anti-aligned with the momentum. For massless particles, such as photons, helizität is a conserved quantity and is directly related to their polarization. In these cases, the helizität can only take on two values, corresponding to left-handed and right-handed polarization.

For massive particles, helizität is not a strictly conserved quantity in the same way as for massless particles. However, it remains a useful descriptor, especially in high-energy interactions. The concept of helizität is crucial for understanding the weak nuclear force, which violates parity symmetry and treats left-handed and right-handed particles differently. Experiments involving neutrinos, for instance, have demonstrated their negative helizität, a key piece of evidence supporting the standard model of particle physics.