The exclusive production of a fully heavy tetraquark and a photon in electron-positron collision

The exclusive production of fully heavy tetraquark ($T(bb\bar{b}\bar{b})$, $T(cc\bar{c}\bar{c})$ and $T(bc\bar{b}\bar{c})$) in association with a hard photon in electron-positron collisions is calculated within the framework of non-relativistic QCD. Both inner structures of molecule-like state and compact state with $J=0,1,2$ for the fully heavy tetraquark are discussed. We find that it is dismal to observe any fully heavy tetraquarks in either the compact configuration or the molecule-like configuration through such exclusive processes at either Belle II or future Z factories like CEPC and FCC-ee.