Measurements of longitudinal flow decorrelations for charged particles are presented in the pseudorapidity range vertical bar eta vertical bar < 1 using a reference detector at 2.5 < eta(ref) < 4 in Au+Au collisions at root s(NN) = 200 GeV by STAR. The factorization ratio (r(n)), which represents the magnitude of decorrelation, shows a strong centrality dependence for the second-order factorization ratio (r(2)), while a weak centrality dependence for the third-order factorization ratio (r(3)). Furthermore, the decorrelation measured at RHIC energy is found to be stronger than that at the LHC energies. Current ideal and viscous hydrodynamic models fail to simultaneously describe the longitudinal flow decorrelations measured at RHIC and the LHC energies.