Properties of π-12C interactions as a function of the cumulative number of π mesons emitted into the backward hemisphere in the laboratory system

Pictures from 2 m propane bubble chamber exposed in the beam of π- mesons with 40 GeV/c momentum have been scanned and diffe- rent characteristics of π-12C - interactions have been studied versus the additive order of cumulativity nsub(C) for πsub(b)-mesons emitted into the backward hemisphere in the laboratory system (l.s.). The study has been performed separately for the numbers of π6 Nsub(πsub(b))=1 and Nsub(πsub(b))>=2. According to the characteristics studied (average momenta in the l.s., average emission angles in the l.s., average rapidities in the pion-nucleon c.m.s. and average multuplicities ), two nsub(C) regions are separated: region 1 (nsub(C)<0.6, Nsub(πsub(b))=1), (nsub(C)<1.0 , Nsub(πsub(b))>=2) and region 2 (nsub(C)>=0.6, Nsub(πsub(h))=1), (nsub(C)>=1.0, Nsub(πsub(b))>=2). Stabilily of the investigated characteristics of π+--mesons and protons is observed as nsub(C) increases in region 2. Some structure ( eak at an angle of theta approximately equal to 60 deg C) is observed in the angular distributions of protons for events with nsub(C)>=0.6