Complete-Coverage Searches for Lorentz Violation in the Minimal Matter Sector

TL;DR

This work addresses the incomplete coverage of Lorentz-violating coefficients in the minimal matter sector of the Standard-Model Extension by introducing a full, high-order boost framework that connects lab-frame signals to Sun-centered coefficients. It analyzes existing high-precision data using extended frame transformations, focusing on the $H_b$ term and tilde coefficients to extract time-dependent signatures across multiple frequencies and latitudes. The main contributions are 43 new first-time limits on tilde coefficients, 13 improvements on previous bounds, and a scalable template to probe up to 49 additional coefficients with future data, dramatically expanding discovery potential in a regime suppressed by higher powers of boost parameters. The results establish near-complete coverage of the minimal matter-sector coefficient space and inform strategies for future experiments across different locations and frequency channels, with implications for other SME sectors and higher-dimension operators.

Abstract

Over the past several decades, dozens of tests have sought Lorentz violation in the nonrelativistic limit of the minimal matter sector of the Standard-Model Extension. Of the 132 Lorentz-violating degrees of freedom that are observable in this limit, 43 remain unconstrained. In this work, we demonstrate how existing experiments and data sets can be used to generate relevant sensitivities to all of these remaining degrees of freedom. We extract limits on all 43 of the previously unconstrained degrees of freedom and make additional improvements on 13 existing limits using published data. Our methods also offer the potential of improvements for 49 degrees of freedom in suitable future experiments. Further, the approach introduced here can be used to leverage data taken at different locations on Earth to achieve independent sensitivities to additional linear combinations of coefficients providing expanded discovery potential.