Dynamics of quark-bag vibrations: validity of the adiabatic approximation

In order to gain an insight into the nature of possible quark–bag vibrations, we consider a schematic "dynamical bag model" for hadrons. The model consists of a spherical bag with an ad hoc inertial mass and surface tension, and the quarks it contains. The bag and quarks are both treated nonrelativistically, and the Schrödinger equation for the coupled bag–quark system is solved. It is found that the adiabatic approximation, which is meant for …