Search for Aligned Events in Muon Groups Deep Underground
  A search for aligned events has been done throughout the muon group events measured with Baksan Underground Scintillation Telescope (BUST) during a long period of time. Only groups of multiplicity >3 for muon threshold energies equal to 0.25; 0.85; 2.0 and 3.2 TeV were selected for the analysis. A distribution of the events on the alignment parameter /lambda has been obtained and compared with the results of Monte-Carlo simulation made for this experiment. Upper limit for aligned muon groups flux is given. 
A.L.Tsyabuk, R.A.Mukhamedshin and Yu.V.Stenkin