New Exotic Meson and Baryon Resonances from Doubly-Heavy Hadronic Molecules

We predict several new exotic doubly-heavy hadronic resonances, inferring from the observed exotic bottomonium-like and charmonium-like narrow states $X(3872)$, $Z_b(10610)$, $Z_b(10650)$, $Z_c(3900)$, and $Z_c(4020\mathrm{/}4025)$. We interpret the binding mechanism as mostly molecular-like isospin-exchange attraction between two heavy-light mesons in a relative S-wave state. We then generalize it to other systems containing two heavy hadrons which can couple through isospin exchange. The new predicted states include resonances in meson-meson, meson-baryon, baryon-baryon, and baryon-antibaryon channels. These include those giving rise to final states involving a heavy quark $Q=c,b$ and antiquark ${\bar{Q}}^{\mathrm{\prime }}=\bar{c},\bar{b}$, namely $D{\bar{D}}^{\ast }$, $D^{\ast }{\bar{D}}^{\ast }$, $D^* B^$,$\bar B B^$,$\bar B^* B^$,$\Sigma_c \bar D^$,$\Sigma_c B^$,$\Sigma_b \bar D^$,$\Sigma_b B^*$,$\Sigma_c \bar \Sigma_c$,$\Sigma_c \bar \Lambda_c$,$\Sigma_c \bar \Lambda_b$,$\Sigma_b \bar \Sigma_b$,$\Sigma_b \bar \Lambda_b$,and$\Sigma_b \bar \Lambda_c$, as well as corresponding S-wave states giving rise to $Q{Q}^{\mathrm{\prime }}$ or $\bar{Q}{\bar{Q}}^{\mathrm{\prime }}$.