Semileptonic Decays of Vector Mesons $$[\rho ,\omega ,\phi ] \to \pi [{{e}^{ + }}{{e}^{ - }},{{\mu }^{ + }}{{\mu }^{ - }}]$$ in a Chiral NJL Model

Abstract

Semileptonic decays of vector mesons $$\rho $$ , $$\omega $$ , ϕ into a pion and lepton pair $${{e}^{ + }}{{e}^{ - }},{{\mu }^{ + }}{{\mu }^{ - }}$$ are described in the chiral Nambu–Jona–Lasinio (NJL) model. Mixing of $$\omega $$ with ϕ is taken into account in a description of vector ϕ meson decay. Direct production via a photon field and production with the participation of intermediate vector mesons $$\rho $$ or $$\omega $$ are taken into account in the production of $${{l}^{ + }}{{l}^{ - }}$$ lepton pairs. The total and differential widths are compared with an experiment. Predictions for $$\rho \to \pi \,\,[{{e}^{ + }}{{e}^{ - }},{{\mu }^{ + }}{{\mu }^{ - }}]$$ and $$\phi \to \pi {{\mu }^{ + }}{{\mu }^{ - }}$$ decays are also given.