Wave functions of S U ( 3 ) pure gauge glueballs on the lattice
The Bethe-Salpeter wave functions of SU(3) pure gauge glueballs are revisited in this study. The ground and the first excited states of the scalar and tensor glueballs are identified unambiguously through the variational method. We calculate the wave functions in the Coulomb gauge and use two lattice spacings to check the discretization artifacts. For the ground states, the radial wave functions are approximately Gaussian, and the size of the tensor glueball is roughly twice as large as that of the scalar glueball. For the first excited states, the radial nodes are clearly observed for both the scalar and the tensor glueballs, such that they can be interpreted as the first radial excitations. These observations may shed light on the theoretical understanding of the inner structure of glueballs.