Triple- X and beyond: Hadronic systems of three and more X(3872)

The $X(3872)$ resonance has been conjectured to be a $J^{PC} = 1^{++}$ charm meson-antimeson two-body molecule. Meanwhile, there is no experimental evidence for larger, few-body compounds of multiple pairs which would resemble larger molecules or nuclei. Here, we investigate such multi-meson states the extent what can deduced theoretically from essentials interaction between uncharged $D^{0}$ and $D^{*0}$ mesons. From molecular $X(3872)$, predict $4X$ ($4^{++}$) octamer with binding energy \mbox{$B_{4X} > 2.08\,{\rm MeV}$,} assuming $D^{*0} \bar{D}^0$ system close unitary limit (as suggested by mass $X(3872)$). If consider heavy-quark spin symmetry explicitly, \bar{D}^{*0}$ ($2^{++}$) unitarity, too. In this case, bound $3X$ ($3^{++}$) hexamer $B_{3X} 2.29\,{\rm MeV}$ more deeply $B_{4X} 11.21\,{\rm MeV}$. These results exemplify hadronic general phenomenon equal-mass two-species Bose systems comprised equal number either type: emergence unbound four- six-boson clusters in short-range acts only bosons different species. Finally, also study conditions under $2X$ tetramer might form.