Baryonium, tetra-quark state and glue-ball in large N_c QCD

TL;DR

This paper investigates various exotic hadronic states such as baryonia, tetra-quarks, hybrids, and glueballs within large N_c QCD, proposing their existence, constructing them from baryons, and predicting their spectra including heavy variants.

Contribution

It provides a theoretical analysis of exotic states in large N_c QCD, identifying their nature, mass estimates, and relations to known particles, including heavy quark extensions.

Findings

Ground state 0^{-+} glueball mass about 2450 MeV

f_0(1710) identified as the lowest 0^{++} glueball

Predicted spectra of heavy baryonia and tetra-quark states

Abstract

From the large-N_c QCD point of view, baryonia, tetra-quark states, hybrids, and glueballs are studied. The existence of these states is argued for. They are constructed from baryons. In N_f=1 large N_c QCD, a baryonium is always identical to a glueball with N_c valence gluons. The ground state 0^{-+} glueball has a mass about 2450 MeV. f_0(1710) is identified as the lowest 0^{++} glueball. The lowest four-quark nonet should be f_0(1370), a_0(1450), K^*_0(1430) and f_0(1500). Combining with the heavy quark effective theory, spectra of heavy baryonia and heavy tetra-quark states are predicted. 1/N_c corrections are discussed.