Statistics of rare multichannel processes and determination of the total cross section of charmed-particle production in the E-161 experiment

The statistics of rare multichannel processes was analyzed and formulas wer e obtained for determining the total cross section of a reaction, the error of the result, and its confidence level. These formulas were used far eval uating the total cross section of charmed-particle production in pp-interat ions at 70 GeV/c in the E-161 experiment with the SVD hybrid setup. The set up incorporated a hydrogen rapid-cycling hubble chamber as a precision vert ex detector and a large-aperture magnetic spectrometer. The detection effic iencies for different topological charm-decay channels were found for the s election criteria assumed in the experiment, using the Monte Carlo simulati on with the PYTHIA and GEANT3 programs. The estimated cross section was obt ained in the form proportional to the number of detected events.