SU3 noninvariance of the vacuum and the chiral-SU2 × SU2-breaking parameter

The effect of SU₃ noninvariance of the vacuum (i.e., f_π≠f_K≠f_η) on the chiral-SU₂ × SU₂-breaking parameter of Gell-Mann, Oakes, and Renner, and on the Gell-Mann-Okubo mass formula for the pseudoscalar meson octet is calculated in a nonlinear Lagrangian model of broken chiral SU₃ × SU₃ symmetry.