Vector and axial vector correlators in a nonlocal chiral quark modelстатья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
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Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 18 июля 2013 г.
Аннотация:The behavior of the non-perturbative parts of the isovector–vector and isovector and isosinglet axial-vector correlators at Euclidean momenta is studied in the framework of a covariant chiral quark model with non-local quark–quark interactions. The gauge covariance is ensured with the help of the P-exponents, with the corresponding modification of the quark–current interaction vertices taken into account. The lowand high-momentum behavior of the correlators is compared with the chiral perturbation theory and with the QCD operator product expansion, respectively. The V − A combination of the correlators obtained in the model reproduces quantitatively the ALEPH and OPAL data on hadronic τ decays, transformed
into the Euclidean domain via dispersion relations. The predictions for the electromagnetic π± −π0 mass difference and for the pion electric polarizability are also in agreement with the experimental values. The topological susceptibility of the vacuum is evaluated as a function of the momentum, and its first moment is predicted to be χ(0) ≈ (50MeV)2. In addition, the fulfillment of the Crewther theorem is demonstrated.