Astrophysical Neutrinos in Testing Lorentz Symmetry

Abstract

An overview of searches related to neutrinos of astronomical and astrophysical origin performed within the framework of the Standard-Model Extension is provided. For this effective field theory, key definitions, intriguing physical consequences, and the mathematical formalism are summarized within the neutrino sector to search for effects from a background that could lead to small deviations from Lorentz symmetry. After an introduction to the fundamental theory, examples of various experiments within the astronomical and astrophysical context are provided. Order-of-magnitude bounds of SME coefficients are shown illustratively for the tight constraints that this sector allows us to place on such violations.

Lorentz Violation in Astroparticles and Gravitational Waves

“…Any type of Lorentz violation introduced at the level of effective field theory can somehow be mapped to the SME; however, the mapping of a specific model may not be obvious at the first place. The articles [11][12][13] provide SME-based analyses and reviews, respectively. The papers [14][15][16][17][18] study phenomena associated with Lorentz violation in specific models and the authors of Refs.…”

“…Reference [13] provides a review of a specific part of the matter sector where gravity plays a minor role: neutrinos. It summarizes the basics of the SME neutrino sector, the formalism incorporating Lorentz violation in neutrinos as well as its implications on physical effects such as neutrino oscillations.…”

Investigation of the Lorentz invariance violation in two-neutrino double-beta decay

“…Of particular interest is the minimal SME, where LIV effects can occur only through operators of mass dimension four or less [4], which represents the theoretical background of many investigations, including those in the neutrino sector. The operators that couple to neutrinos can affect the neutrino oscillations, neutrinos velocity, and spectra of the electrons emitted in beta and double-beta decays [5][6][7][8][9][10].…”