Search for Aligned Events in Muon Groups Measured by BUST

A search for aligned events has been done throughout the muon groups events measured by Baksan Underground Scintillation Telescope (BUST) during a period of 7.7 years. Only groups of multiplicity $>3$ for muon threshold energy equal to 0.85 TeV were selected for the analysis. A distribution of the events on alignment parameter $\lambda$ has been obtained and compared with the results of Monte-Carlo simulation made for this experiment. The upper limit for aligned muon event flux as low as $5.3\cdot {10}^{-15}$ $c{m}^{-2}se{c}^{-1}s{r}^{-1}$ is given.