# Computation of Four-Body Phase Space

Hallo everybody!

I’m new in using ROOT, so I’m sorry if the following is a stupid question…

I urgently need to calculate the completely integrated relativistic four-body phase space, i.e. the integral

Thereby, sqrt(s) is the given c.m. energy, and furthermore all of the four outgoing particles have equal mass m. In principle, I wanted to use the class TGenPhaseSpace, but I don’t really knowhow to use it in order to get simply the whole integrated phase space…
By the way, any constant factors (which don’t depend on m or sqrt(s)) in the phase space integral are irrelevant for my purposes.

Thank you a lot,
Best

Sebastian