Central emission of pions and search for a symmetry system

Abstract Results are presented on the production of pions having the same direction as the incident particles, but opposite charge, in reactions of π + p at 8 and 16 GeV/ c , π − p at 16 GeV/ c and K − p at 10 GeV/ c . The d σ/ d p L ∗ distributions in the region ¦p L ∗ ¦ GeV /c are of the form exp (−A¦p L ∗ ¦) , with unequal values of A in the forward and backward directions. A study is made of this asymmetry as a function of the mass and energy of the incoming particle.