Research on the phase space of three- and four-body final states processes

Analytical formulae for the phase space factors and three-momenta of three- and four-body final states are derived for all sets of independent kinematic variables containing invariant mass variables. These formulae will help experimental physicists to perform data analysis. As an example, we show how to use these formulae to distinguish the different mechanisms of the e + p -> e J/psi + p process when searching the signals P-c of states in the energy region of the Electron-Ion collider at China (EicC).

Automated summary

Analytical formulae for the phase space factors and three-momenta of three- and four-body final states are derived for all sets of independent kinematic variables containing invariant mass variables. These formulae will assist experimental physicists in data analysis. As an example, the formulae are applied to distinguish different mechanisms in the e + p -> e J/psi + p process at the Electron-Ion collider in China's energy region, aiding the search for signals of P-c states.