Doubly heavy baryons at LHC

The theoretical analysis of production, lifetime, and decays of doubly heavy baryons is presented. The lifetime of $\Xi_{cc}^{++}$ baryon recently measured by the LHCb Collaboration is used to estimate the lifetimes of other doubly heavy baryons. The production and the possibility of observation of $\Xi_{bc}$ baryon at LHC are discussed.