Unflavored Excitations of Nucleon-Nucleon States in Terms of a First-Order Mass Formula

Abstract

The possibility that hadrons could exist with structures beyond conventional qq or qqq quark configurations was noted by Gell-Mann1. Clement et _al_.2 provide an example of these exotic hadrons in the unflavored dibaryon sector as illustrated through both elastic nucleon-nucleon (NN) scattering and NN-induced pion production. Clement et _al_.2 address three specific unflavored excitations of the nucleon: (1) X(2148) Jπ=2+, X(2140) Jπ=1+, and d*(2380) Jπ=3+. These states are addressed in terms of a first-order hexaquark mass formula as proton (uud) and neutron (ddu) baryon clusters. The first-order hexaquark model predicts a state with a mass of 2180 MeV/c2 with a Jπ = 0+ or 1+ spin assignment. The model mass result is within 2% of the X(2140) J=1+ state.