Stress out of charmonia

We investigate the gravitational form factors of charmonium. Our method is based on a Hamiltonian formalism on the light front known as basis light-front quantization. The charmonium mass spectrum and light-front wave functions were obtained from diagonalizing an effective Hamiltonian that incorporates confinement from holographic QCD and one-gluon exchange interaction from light-front QCD. We proposed a quantum many-body approach to construct the hadronic matrix elements of the energy momentum tensor T^++ and T^+-, which are used to extract the gravitational form factors A(Q^2) and D(Q^2). The obtained form factors satisfy the known constraints, e.g. von Laue condition. From these quantities, we also extract the energy, pressure and invariant mass squared distributions of the system. We find that hadrons are multi-layer systems. We also find that there is a tachyonic core within charmonium.