  We describe an approximate quantum mechanical picture of hadrons in Minkowski
space in the context of a renormalization group procedure for effective
particles (RGPEP) in a light-front Hamiltonian formulation of QCD. The picture
suggests that harmonic oscillator potentials for constituent quarks in lightest
mesons and baryons may result from the gluon condensation inside hadrons,
rather than from an omnipresent gluon condensate in vacuum. The resulting
boost-invariant constituent dynamics at the renormalization group momentum
scales comparable with Lambda_QCD, is identified using gauge symmetry and a
crude mean-field approximation for gluons. Besides constituent quark models,
the resulting picture also resembles models based on AdS/QCD ideas. However,
our hypothetical picture significantly differs from the models by the available
option for a systematic analysis in QCD, in which the new picture may be
treated as a candidate for a first approximation. This option is outlined by
embedding our presentation of the crude and simple hadron picture in the
context of RGPEP and a brief outlook on hadron phenomenology. Several
appendices describe elements of the formalism required for actual calculations
in QCD, including an extension of RGPEP beyond perturbation theory.
