Chiral fermions, massless particles and Poincare covariance

TL;DR

This paper develops a Hamiltonian framework for massless particles of any helicity using the coadjoint orbit method, clarifying their transformation properties under Poincare symmetry.

Contribution

It introduces a novel Hamiltonian formulation for massless particles with arbitrary helicity, employing nonlinear realizations of the Poincare group.

Findings

Hamiltonian dynamics constructed for massless particles of arbitrary helicity

Transformation properties of variables interpreted via nonlinear Poincare realizations

Action principle formulated with new space-time variables with standard transformations

Abstract

The coadjoint orbit method is applied to the construction of Hamiltonian dynamics of massless particles of arbitrary helicity. The unusual transformation properties of canonical variables are interpreted in terms of nonlinear realizations of Poincare group. The action principle is formulated in terms of new space-time variables with standard transformation properties.