Pseudoscalar-meson-octet-baryon coupling constants in two-flavor lattice QCD

Abstract

We evaluate the πΝΝ, π∑∑, πΛ∑, KΛN and K∑N coupling constants and the corresponding monopole masses in lattice QCD with two flavors of dynamical quarks. The parameters representing the SU(3)-flavor symmetry are computed at the point where the three quark flavors are degenerate at the physical s-quark mass. In particular, we obtain α ≡ F/(F+D) = 0.395(6). The quark-mass dependences of the coupling constants are obtained by changing the u- and the d-quark masses. We find that the SU(3)-flavor parameters have weak quark-mass dependence and thus the SU(3)-flavor symmetry is brokenby only a few percent at each quark-mass point we consider.