Based on the quark propagator derived in the instanton dilute liquid approximation, the quark condensate susceptibilities have been calculated at the mean-field level in a nonperturbative QCD model. The numerical resu...Based on the quark propagator derived in the instanton dilute liquid approximation, the quark condensate susceptibilities have been calculated at the mean-field level in a nonperturbative QCD model. The numerical results are compatible with the values obtained within other nonperturbative approaches. The calculated masses and decay constants of π and σ mesons are close to the experimental values. These results show that the instanton medium might be a good approximation of the QCD vacuum.展开更多
Based on a modified version of the global color symmetry model,the pion susceptibilities of vacuum needed in the QCD sum rule external-field method for the coupling of pseudoscalar current to hadron have bean calculat...Based on a modified version of the global color symmetry model,the pion susceptibilities of vacuum needed in the QCD sum rule external-field method for the coupling of pseudoscalar current to hadron have bean calculated beyond the vacuum saturation approximation.Comparison with the previous estimations has been given.展开更多
文摘Based on the quark propagator derived in the instanton dilute liquid approximation, the quark condensate susceptibilities have been calculated at the mean-field level in a nonperturbative QCD model. The numerical results are compatible with the values obtained within other nonperturbative approaches. The calculated masses and decay constants of π and σ mesons are close to the experimental values. These results show that the instanton medium might be a good approximation of the QCD vacuum.
文摘Based on a modified version of the global color symmetry model,the pion susceptibilities of vacuum needed in the QCD sum rule external-field method for the coupling of pseudoscalar current to hadron have bean calculated beyond the vacuum saturation approximation.Comparison with the previous estimations has been given.