Search for the doubly heavy baryon ■ decaying to ■

A first search for the ■decay is performed by the LHCb experiment with a data sample of proton-proton collisions, corresponding to an integrated luminosity of 9 fb^-1 recorded at centre-of-mass energies of 7, 8, and 13 TeV. Two peaking structures are seen with a local(global) significance of 4.3(2.8) and 4.1(2.4) standard deviations at masses of 6571 and 6694 MeV/c², respectively. Upper limits are set on the ■ baryon production cross-section times the branching fraction rela...