Possible mass-spin relation for the hadron resonances as an extended object

The results on mass-spin relation are presented, based on the assumption that hadron resonances construct a (2+1) 3-dimensional world with constant curvature in (3+1) flat Minkowski space. It is shown that the qualitative features of hadron mass spectrum are obtained from the mass eigenvalue equation under a suitable boundary condition related to the extensions of the excited states of hadrons in Minkowski space-time. If the fundamental physical constant of strong interaction l is quantized (lsub(s1), lsub(s2),...), ordinary hadron resonances consisting of u, d, s quarks are explained by lsub(s1),...,lsub(s8) and the critical values lsub(s1), lsub(s3), lsub(s9) correspond to the masses of t, b, c quarks respectively. Motivated by these results, it is possible to have the idea that the quark structure of hadrons can be reduced to the properties of internal space-time itself