Dynamical chiral-symmetry breaking and determination of the quark masses

Using an effective-potential approach for composite operators, we study dynamical symmetry breaking in QCD-like theories with massless quarks. The analysis is extended to massive quarks in QCD with three flavors and the masses of the pseudoscalar-octet mesons and their decay constants are calculated. Renormalization-group corrections are taken into account. The effective potential depends on the standard parameters of QCD: ${\Lambda }_{\mathrm{QCD}}$, $m_u$, $m_d$, $m_s$ and on a mass scale μ which discriminates between the infrared and the ultraviolet regimes. A good fit for the meson masses (agreement within 3%) and for the decay constants is obtained for the following values of the quark masses at 1 GeV: $m_u$=5.8 MeV, $m_d$=8.4 MeV, and $m_s$=118 MeV. These values essentially agree with the values obtained by quite different methods.