Displaced $B_c^-$ mesons as an inclusive signature of weakly decaying double beauty hadrons

Abstract

The recent discovery, by the LHCb collaboration, of the $\Xi_{cc}^{++}$ doubly charmed baryon, has renewed interest in the spectroscopy of doubly heavy hadrons. Experimentally, however, searches for such states appear highly challenging. The reconstructed final states tend to involve multiple heavy flavoured (beauty or charm) hadrons, so the yield for any exclusive decay mode will be suppressed to unobservably low levels by the product of several branching fractions, each of which is typically $10^{-3}$--$10^{-2}$. Noting that decays of double beauty hadrons are the only possible source of $B_c^-$ mesons that are displaced from the primary vertices of proton-proton collisions at the LHC, a more promising inclusive search strategy is proposed.