Gauss Integration over Relativistic 3--Body Phase Space for   1--Dimensional Distributions of $ 2 \to 3 $ Reaction
  We present the analysis of the phase space geometry of 2 $\rightarrow$ 3 reaction for the general case of nonzero and unequal particle masses. Its purpose is to elaborate an alternative approach to the problem of integration over phase space which does not exploit the Monte Carlo principle. The fast and effective algorithm of integration based on Gauss method is developed for treating 1--dimensional distributions in two--particle invariant variables. The algorithm is characterized by significantly improved accuracy and it can meet requirements of interactive processing. 
A.A. Bolokhov (1), P.A. Bolokhov (1), T.A. Bolokhov (1) and S.G.   Sherman (2) ((1) St. Petersburg State University, (2) St....