A role of the axial-vector mesons on the photon production in heavy-ion collisions and their relevant decays

A role of the axial-vector mesons. such as K-1 and a(1), on the emitted-photon spectrum in hot hadronic matter is studied through the channels pirho --> a(1) --> pigamma and Krho --> K-1 --> Kgamma. Both channels could be dominant over the region lower than Egamma similar to 0.5 GeV, while the role of the K-1 meson is diminished in the higher E-gamma region. This study is carried out with an SUL(3) circle times SUR(3) effective chiral Lagrangian which includes vector and axial-vector mesons systematically and explains well their hadronic and radiative decays simultaneously.