X(5) Critical symmetry with inverse square potential via a variational procedure K. R. Ajulo, K. J. Oyewumi, O. S. Oyun and S. O. Ajibade Eur. Phys. J. Plus, 137 1 (2022) 90 Published online: 05 January 2022 DOI: 10.1140/epjp/s13360-021-02276-0