Unified formulation for helicity and continuous spin fermionic fields

Abstract

We propose a unified BRST formulation of general massless fermionic fields of arbitrary mixed-symmetry type in $d$-dimensional Minkowski space. Depending on the value of the real parameter the system describes either helicity fields or continuous spin fields. Starting with the unified formulation we derive a number of equivalent descriptions including the triplet formulation, Fang-Fronsdal-Labastida formulation, light-cone formulation and discuss the unfolded formulation.

v2: exposition of the triplet formulation is improved and the triplet Lagrangian for fermionic helicity fields is made precise, references and acknowledgements added; v4: corrected typos, reference and comments added