The axial-vector meson a1 (1260) as a molecular state

초록

We investigate the axial-vector meson a1 (1260) resonance from πρ scattering based on the fully off-mass-shell coupled-channel formalism. The πρ channel is coupled to the KK?* channel, which generates the a1 (1260) below the KK?* threshold. This shows a certain similarity to the scalar meson f0 (980) resonance that arises as a KK? molecular or quasi-bound state. This implies that the a1 (1260) resonance can be theoretically interpreted as the KK?* molecular state. As a result, the experimental data on the total cross section of πρ scattering are described very well by this πρ and KK?* coupled channels.