Phase-Space Considerations for Five-Particle Final States

This paper gives detailed and explicit discussion of five-particle phase space in terms of invariant variables. The distribution of final states, after taking account of energy and momentum conservation, is integrated over orientations of the entire system and then expressed in terms of squares of invariant masses. The results permit analysis for two-, three-, and four-particle resonances. Formulas are given for the boundary of the allowed region in the eight dimensions and for the distribution of final states inside, together with several of the simpler distributions which result when integrations can be made over some of the invariant masses.