Molecular nature of the $a_1$(1260) axial-vector meson

Abstract

We investigate $\pi \rho$ scattering based on the coupled-channel formalism with the $\pi \rho$ and $K{\bar{K}}^{\ast }$ ($\bar{K}{K}^{\ast }$) channels included. We construct the kernel amplitudes by using the meson-exchange model and compute the coupled integral equation for $\pi \rho$ scattering. By performing the partial-wave expansion, we show explicitly that the $a_1(1260)$ meson is dynamically generated by the coupled-channel formalism. The $a_1$ meson only appears by including the $K{\bar{K}}^{\ast }$ ($\bar{K}{K}^{\ast }$) channel. We obtain the pole position of the $a_1$ meson as $\sqrt{s_R}=(1170.7-i173.0)$ MeV. We conclude that the $a_1$ meson can be interpreted as a kaon and vector kaon molecular state.

8 pages and 4 figures. The results are updated

References in corpus (5)

• Extraction of Resonances from Meson-Nucleon Reactions
• Study the molecular nature of $\sigma$, $f_0(980)$, and $a_0(980)$ states
• Electromagnetic transitions of the singly charmed baryons with spin 3/2
• Evidence of the four-quark nature of $f_0(980)$ and $f_0(500)$
• Analysis on the composite nature of the light scalar mesons $f_0(980)$ and $a_0(980)$

Cited by in corpus (2)

• Triple-strangeness hidden-charm pentaquarks
• Measurement of the branching fractions of $\bar{B}\to D^{(\ast )}{K}^{-}{K}_{(S)}^{(\ast )0}$ and $\bar{B}\to D^{(\ast )}{D}_s^{-}$ decays at Belle II