Chiral oscillations

¹ Max Planck Institute for the Science of Light - Staudtstr. 2, PLZ 91058 Erlangen, Germany
² Departamento de Física, Universidade Federal de São Carlos - P.O. Box 676, 13565-905 São Carlos, Brazil
³ Dipartimento di Fisica, Università degli Studi di Salerno - Via Giovanni Paolo II, 132, 84084 Fisciano, Italy
⁴ INFN, Sezione di Napoli, Gruppo Collegato di Salern - 80126 Naples, Italy

^(a) mblasone@unisa.it (corresponding author)

Received: 18 June 2022
Accepted: 26 July 2022

Abstract

The solutions of the Dirac equation are given in terms of bispinors, four-component objects which include both spin and chirality as internal degrees of freedom. For massive particles, the Dirac equation couples components of the bispinor with different chiralities, yielding chiral oscillations. This phenomenon can be particularly relevant for recent proposals aimed at measuring non-relativistic cosmic neutrinos, and can find analogies in Dirac-like systems, such as graphene. In this paper, a concise review of chiral oscillations is presented, including their description with the Dirac's equation dynamics and the underlying group structure. Two paradigmatic cases of chiral oscillations in physical systems are shown: the effects on lepton-antineutrino spin quantum correlations, and neutrino flavor oscillations. Finally, extensions of recent theoretical investigations as well as future research developments are discussed.