Decay rates f1(1285) → ρ0π+π– and a1(1260) → ωπ+π– in the Nambu – Jona-Lusinio model
Seminars
Seminar on Hadron Physics
Date and Time: Friday, 25 May 2018, at 11:00 AM
Venue: Blokhintsev Hall (4th floor), Bogoliubov Laboratory of Theoretical Physics
Seminar topic: «Decay rates f1(1285) → ρ0π+π– and a1(1260) → ωπ+π– in the Nambu – Jona-Lusinio model»
Authors: A.A. Osipov, A.A. Pivovarov, M.K. Volkov
Speaker: A.A. Osipov
Abstract:
The anomalous decays f1(1285) → ρ0π+π– violating natural parity for vectors and axial-vectors are studied in the framework of the Nambu — Jona-Lasinio model. We consider the Lagrangian with U(2)L x U(2)R chiral symmetric four quark interactions. The theory is bosonized and corresponding effective mason verticles are obtained in the leading order of 1/Nc 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 Г(f1(1285) —> ρ0π+π–=2.78 MeV and Г(a1(1260) → ωπ+π–)=87 keV. Our result on the f1(1285) —> ρ0π+π– decay rate is in a good agreement with experiment. It is shown that a strong suppression of the a1(1260) → ωππ decay is a direct consequence of destructive interference between box and triangle anomalies.