Constraining the isotropic CPT-odd coefficients of the Standard Model Extension by a combined DUNE and ESSnuSB analysis

Based on an analysis that considers the isotropic CPT-odd Standard Model Extension (SME) coefficients, we find new constraints for them coming from a combined DUNE and ESSnuSB fit. Furthermore, we investigate the correlations of the standard oscillation parameters, the leptonic CP-violating phase, ${\delta }_{CP}$, and the atmospheric mixing angle, ${\sin }^2{\theta }_{23}$, with respect to the SME coefficients $(a_L{)}^T$. The combination of DUNE and ESSnuSB may establish the strongest limit on the diagonal coefficient $(a_L{)}_{\mu \mu }^T$ compared to the existing limits in the literature. We also consider the possible effect of the SME coefficient $(a_L{)}^Z$ on neutrino propagation and discuss how this can affect DUNE limits on the coefficient $(a_L{)}^T$ found elsewhere.