A Unified Study of Hidden-Charm and Hidden-Bottom Mesons

We present a unified phenomenological analysis of hidden-charm and hidden-bottom mesons, treating the $c\bar c$ and $b\bar b$ sectors within a common screened-potential and QCD sum-rule framework. The mass spectra are obtained from a screened Coulomb-plus-confining interaction with spin-dependent corrections, while the short-distance decay constants, annihilation widths and electromagnetic transition form factors are organized through two-point and three-point QCD sum rules. The same calculated states are then used to study E1 and M1 radiative transitions, Regge trajectories and finite-spectrum thermodynamic observables constructed from excitation energies relative to the corresponding ground states. The results are discussed together rather than as disconnected outputs: the mass spectra determine the state assignments, the Regge plots test the global level ordering, the radiative widths probe orbital and spin-flip overlap integrals, and the QCD sum-rule quantities connect the spectrum to current-coupled observables. The comparison of the two hidden-flavour sectors shows the expected compression and stronger spin suppression in bottomonium, while charmonium remains more sensitive to fine-structure, radial-node and medium-related effects. The resulting picture provides a coherent vacuum benchmark for $c\bar c$ and $b\bar b$ spectroscopy, radiative transitions and QCD sum-rule observables.