  Mass spectra of ground state hadrons containing u-, d-, s-, c-quarks as well
as some lightest hadrons containing b-quarks are calculated on the basis of a
slightly modified bag model. The center-of-mass motion corrections are
incorporated using a wavepacket projection with Gaussian parametrization of the
distribution amplitude. We use running coupling constant and also allow the
effective quark mass to be scale-dependent. The impact of these modifications
on the hadron mass spectrum is investigated. A comparison of the predicted mass
values with the experimental data demonstrates that the modified bag model is
sufficiently flexible to provide a satisfactory description of light and heavy
hadrons (mesons and baryons) in a single consistent framework.
