Relativity violations and beta decay

In some quantum theories of gravity, deviations from the laws of relativity could be comparatively large while escaping detection to date. In the neutrino sector, precision experiments with beta decay yield new and improved constraints on these countershaded relativity violations. Existing data are used to extract bounds of $3 \times 10^{-8}$ GeV on the magnitudes of two of the four possible coefficients, and estimates are provided of future attainable sensitivities in a variety of experiments.