Observations of single bunch beam-beam coherent modes during dedicated
experiments in the LHC are presented. Their role in standard operation for
physics is discussed and, in particular, candidates of beam-beam coherent mode
driven unstable by the machine impedance are presented.Comment: 4 pages, contribution to the ICFA Mini-Workshop on Beam-Beam Effects
in Hadron Colliders, CERN, Geneva, Switzerland, 18-22 Mar 201