A meson-baryon bound state in a 2 + 1 lattice QCD model with two flavours and strong coupling.

Abstract

We consider the existence of bound states of one meson and one baryon in an imaginary-time formulation of lattice quantum chromodynamics (QCD). We analyse an SU(3) theory with two flavours in 2 + 1 dimensions and two-dimensional (2D) spin matrices. For small hopping parameter 0 < 1 and sufficiently large glueball mass, i.e., in the strong coupling limit, restricting our analysis to the 1/2 total isospin sector, we show the existence of a meson-baryon bound state solution to the Bethe–Salpeter (B–S) equation in a ladder approximation below the meson-baryon threshold ( −5ln ), and with binding energy of strength 0.1081 2. The existence of the bound state is an effect of two sources of attraction, a zero-range energy dependent potential and a space range-one potential associated with a quark anti-quark exchange.