The experimental feature on the data of the primary proton   identification in stratospheric X-ray emulsion chambers at energies >10 TeV   (RUNJOB experiment)
  The RUNJOB balloon-born emulsion chamber experiments have been carried out for investigating the composition and energy spectra of primary cosmic rays at energies 10-1000 TeV/nucleon. On the data of the treatment of RUNJOB` X-ray emulsion chambers exposed since 1995 to 1999 year about 50 % proton tracks were identified. In remained half of the events from proton group the one charged primary tracks were not found in the search area determined with high accuracy by the triangulation method using the several background heavy tracks. Considered methodical reasons in this paper could not explain this experimental result. The one from the probable physical reasons that is the neutrons in cosmic ray flux does not explain it too. 
I.S.Zayarnaya