[@Roca:2005nm]. The work in Refs. [@Lutz:2003fm; @Roca:2005nm], using the lowest order chiral Lagrangian, has been extended in Ref. [@Zhou:2014ila] including higher order terms, but in the case of the $f_1(1285)$ the higher order terms were found essentially negligible.

In this picture for the $f_1(1285)$, a good description of $\pi a_0(980)$ and the isospin forbidden $\pi f_0(980)$ decay modes were well reproduced [@Aceti:2015zva]. Actually the $\pi f_0(980)$ decay mode was first predicted in Ref. [@Aceti:2015zva] and corroborated later experimentally by a BESIII experiment [@Ablikim:2015cob]. Similarly, in Ref. [@Aceti:2015pma] the $K \bar K \pi$ decay mode was studied and also found consistent with experiment [@Barberis:1997vf; @Barberis:1998by]. In the present work, we shall see that, as a consequence of the $K^* \bar K$ nature of the $f_1(1285)$, if we excite that state and go to higher energies where the $K^* \bar K$ can be produced, the tail of the $f_1(1285)$ propagator, together with the phase space for $K^* \bar K$ production, produce a peak around 1420 MeV with a width of about 60 MeV, that explains the experimental features observed for the $f_1(1420)$ resonance.

On the other hand, the triangle diagram with $K^* \bar K K$ intermediate states, with $\pi$ and $f_0(980)$ or 