We develop an alternative scheme of spontaneous chiral symmetry breaking which is characterized by four-quark condensates instead of (7jq),*O. In this scheme the Nambu-Goldstone bosons acquire a mass squared - m~uark' in comparison with mquark in the usual scheme. The quark mass ratios and the parameters of the scheme are determined by an application to the pseudoscalar nonet spectrum (including 'lT0_'Yj_'Yj' mixing). The decays Iji -+('lT0 , 'Yj, 'Yj}y and Iji' -+ 1ji('lT0 , 'Yj) are also considered. The results do not promote the alternative scheme.
Spontaneous chiral symmetry breaking in lattice QCD is studied by calculating special four fermion correlation functions using the Monte Carlo method. In the continuum theory in the limit of short distance and small mass these functions are related to the order parameter [Formula: see text]. We found a range of quark mass for which the predicted relations approximately hold, using the Susskind formulation of fermions. However, we encountered a theoretical problem in the latter formulation concerning the short distance behavior of the correlation functions of different spin and flavor. This may cast some doubt on the interpretation of spin and flavor in this formulation.
On the role of dynamical quark mass generation in chiral symmetry breaking in QCD
