Naslov
Quark loop calculation of the gamma -> 3 pi form factor

Autori
Bistrović, Bojan ; Klabučar, Dubravko

Izvornik
Physical Review D (0556-2821) 61 (2000), 3;

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Axial anomaly; Quark loops; Box graph; Constituent quarks

Sažetak
The presently experimentally interesting form factor for the anomalous process gamma -> pi^+ pi^0 pi^- is calculated as the quark "box"-amplitude where the intermediate fermion loop is the one of constituent quarks with the pseudoscalar coupling to pions. This also corresponds to the form factor, in the lowest order in pion interactions, of the sigma-model and of the chiral quark model. We give the analytic expression for the form factor in terms of an expansion in the pion momenta up to the order O(p^8) relative to the soft point result, and also perform its exact numerical evaluation. We compare our predictions with those of the vector meson dominance and chiral perturbation theory, as well as with the scarce data available so far.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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