paper

Decay rates and in the Nambu -- Jona-Lasinio model

arXiv:1805.10907 · doi:10.1103/PhysRevD.98.014037

Abstract

The anomalous decays and violating natural parity for vectors and axial-vectors are studied in the framework of the Nambu -- Jona-Lasinio model. We consider the Lagrangian with chiral symmetric four quark interactions. The theory is bosonized and corresponding effective meson vertices are obtained in the leading order of and derivative expansions. The uncertainties related with the surface terms of anomalous quark triangle diagrams are fixed by the corresponding symmetry requirements. We make a numerical estimate of the decay widths $Γ(f_1(1285)\toρ^0π^+π^-)=2.78\, \mbox{MeV}$ and $Γ(a_1(1260)\toωπ^+π^-)=87\, \mbox{keV}$. Our result on the decay rate is in a good agreement with experiment. It is shown that a strong suppression of the decay is a direct consequence of destructive interference between box and triangle anomalies.

10 pages, 6 figuras

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