On Understanding QCD Condensates from Hadron Spectroscopy

W -Y. P. Hwang ； A. N. Mitra ； Kwei-Chou Yang

《Chinese Journal of Physics》 33卷4期 (1995/08) Pp. 397-417

並列摘要

We investigate in a specific and systematic manner the possibility of understanding some of the principal QCD condensates〈qOq〉, which are traditionally associated with QCD sum rules, directly in terms of their definition, viz., - ∫d^4pTr{S^A(subscript F)(p)O} where the quark propagator S^A(subscript F)(p) is so defined that the perturbative part is suitably subtracted. To this end, we relate the mass function m(p^2) to the pion-quark vertex function in the chiral limit. This last aspect provides a concrete handle for its determination through the vehicle of the Bethe-Salpeter equation (BSE) for qq hadrons. Since the latter is directly adaptable to spectroscopic studies, the method provides a clear linkage between the high-energy and low-energy descriptions of hadrons in QCD. The gluon condensate which is related to the same qq interaction in the confining region (the infrared domain of the gluon propagator) may also be calculated in a similar fashion. The results for most condensates are in good overlap with the values employed in the method of QCD sum rules.