Speaker
Description
The $u\overline{u}c\overline{c}$, $u\overline{u}b\overline{b}$, and $u\overline{u}s\overline{s}$ $J^{PC}=1^{--}$ states are investigated by a coupled-channel two-meson model. We used the complex scaling method with 14 two-meson channels with an effective hadron interaction originated from interaction between quarks. The coupling between channels is obtained from the quark rearrangement.
We have found a pole each in the $u\overline{u}c\overline{c}$ and in the $u\overline{u}s\overline{s}$ systems. The pole in the hidden charm system appears 1 MeV below the $\overline{D}D_1'$ threshold, 4289 MeV, with a few MeV width. A similar pole appears just below $\overline{K}^*K_1$ threshold, 2163 MeV, in the hidden strange system. We argue that they are important components of $Y(4260)$ or $\phi(2170)$, respectively, which are considered to be exotic mesons.
