We mapped the relaxation times of inter- and intramolecular correlations in o-terphenyl by a quasielastic scattering method using nuclear resonant scattering of synchrotron radiation. From the obtained map, we found that the slow beta process is decoupled from the alpha process at 278 K, and this temperature is clearly below the previous decoupling temperature of 290 K, at which the alpha-relaxation dynamics changes. Then, it was also concluded that sufficient solidlike condition achieved by further cooling from 290 K is required to decouple the slow beta process from the alpha process and, due to the difference of the length scales between the alpha and the slow beta processes, these two averaged relaxation times <tau > are concluded not to cross as an extrapolation assumed so far. Furthermore, evidence of the restricted dynamics of the slow beta process could be obtained as an anomalous momentum transfer (q) dependence of <tau >(<tau > proportional to q(-2.9)) at 265 K, observed at q values of 18-48 nm(-1).