Doubly heavy hadron production in ultraperipheral collisions

The inclusive production of pseudoscalar heavy quarkonia ($\eta_c,\, \eta_b,\, B_c$), double heavy baryons $\Xi_{QQ^\prime}$ ($Q^{(\prime)}=c,\,b$ quarks) and tetraquarks $T_{QQ}$ in heavy ion ultraperipheral collisions (UPCs) is studied. Numerical results indicate that the experimental investigation of $\eta_c,\, \Xi_{cc}$, and $T_{cc}$ is feasible at the upcoming HL-LHC and future FCC. Heavy ion UPCs open another avenue for studying the production of these doubly heavy hadrons.