Excited Hadrons and Quark-Hadron Duality

Abstract

We review how Quark-Hadron Duality (QHD) for (u,d) flavors at high energies and in the scaling regime suggests a radial and angular behaviour of mesonic and baryonic resonance masses of the Regge form $M_{nJ}^2={\mu }^{2}n+{\beta }^{2}J+M_0^2$. The radial mass dependence is asymptotically consistent with a common two-body dynamics for mesons and baryons in terms of the quark-antiquark ($q\bar{q})$ and quark-diquark ($qD$) degrees of freedom, respectively. This formula is validated phenomenologically within an uncertainty determined by half the width of the resonances, $\Delta M_{nJ}^2\sim {\Gamma }_{nJ}{M}_{nJ}$. With this error prescription we find from the non-strange PDG hadrons different radial slopes ${\mu }_{\bar{q}q}^2=1.34(4){\mathrm{GeV}}^2$ and ${\mu }_{qD}^2=0.75(3){\mathrm{GeV}}^2$, but similar angular slopes ${\beta }_{\bar{q}q}^2\sim {\beta }_{qD}^2\sim 1.15{\mathrm{GeV}}^2$.

Comments: 6 pages, 4 figures, Acta Physica Polonica B style, talk by E. Ruiz Arriola at workshop "Excited QCD 2017", Sintra, Portugal, May 7-13, 2017