Eur. Phys. J. Special Topics 229, 2003–2022 (2020)
https://doi.org/10.1140/epjst/e2020-900277-x

Review

Spin-half mass dimension one fermions and their higher-spin generalizations

Center for Theoretical Physics, College of Physical Science and Technology, Sichuan University, Chengdu 610064, P.R. China

^a e-mail: cylee@scu.edu.cn

Received: 8 December 2019
Accepted: 22 July 2020
Published online: 21 September 2020

Abstract

A self-contained review on spin-half mass dimension one fermions and their higher-spin generalizations is presented. Starting from the two-component left-handed Weyl spinors, the Dirac spinors and Elko (eigenspinors of the charge conjugation operator) are constructed. After elaborating on their similarities and differences, we generalize the spin-half Elko to higher-spin. The field operators constructed from Elko and their higher-spin generalizations are shown to be of mass dimension one with positive-definite free Hamiltonians. The physical significance of higher-spin mass dimension one particles and further extensions in the context of Lounesto classification are discussed.