Key points are not available for this paper at this time.
Simple example of the light front construction of valent quark model of hadrons is presented which allows to classify the hadron states in orbital momentum and spin via introducing the spectral wave functions that depend on spatial coordinates of quarks. These wave functions correspond to the mass squared spectrum of hadrons and can be related to the spectrum of 3-dimensional quantum harmonic oscillator.
Malyshev et al. (2025) studied this question.