2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/36753Theoretically a possibility of covariance violation in weak decays is not ruled out from the first principles, while there are some models predicting non-covariance revealed in weak interactions. The experimental evidence for isotropy violation in $β$-decays was recently reported. We present a study of the dependence of electron flow rate and $β$-electron energy in the decay of $Sr^{90}$ with respect to the direction of electron emission. An upper limit of $1.4 \cdot 10^{-5}$ on directional dependence of $β$-electron energy was obtained.8 pages, 5 figuresHigh Energy Physics - Experimenttext