Spin half fermions with mass dimension one: theory, phenomenology, and dark matter

TL;DR

This paper introduces a novel spin-half fermion with mass dimension one, exploring its theoretical properties, potential as dark matter, and implications for cosmology and particle physics.

Contribution

It presents the first detailed theory of a spin-half fermion with mass dimension one, including its unique properties, interactions, and potential role as dark matter.

Findings

Fermion exhibits non-locality and belongs to a non-standard Wigner class.

The particle is a viable dark matter candidate with a preferred mass around 20 MeV.

Constraints from supernova-like explosions suggest specific mass and cross-section values.

Abstract

We provide the first details on the unexpected theoretical discovery of a spin-one-half matter field with mass dimension one. It is based upon a complete set of dual-helicity eigenspinors of the charge conjugation operator. Due to its unusual properties with respect to charge conjugation and parity, it belongs to a non-standard Wigner class. Consequently, the theory exhibits non-locality with (CPT)^2 = - I. We briefly discuss its relevance to the cosmological `horizon problem'. Because the introduced fermionic field is endowed with mass dimension one, it can carry a quartic self-interaction. Its dominant interaction with known forms of matter is via Higgs, and with gravity. This aspect leads us to contemplate the new fermion as a prime dark matter candidate. Taking this suggestion seriously we study a supernova-like explosion of a galactic-mass dark matter cloud to set limits on the mass of the new particle and present a calculation on relic abundance to constrain the relevant cross-section. The analysis favours light mass (roughly 20 MeV) and relevant cross-section of about 2 pb. Similarities and differences with the WIMP and mirror matter proposals for dark matter are enumerated. In a critique of the theory we bare a hint on non-commutative aspects of spacetime, and energy-momentum space.