A study of contact processes in Coulomb three-body systems with unit charges

The contact processes between positive particles from the ground bound states of Coulomb three-body systems with unit charges such as X + Y + Z $ are considered. The probability amplitude for the contact processes is proportional to the expectation value of the respective Dirac delta function, e.g., ( delta (r ++ ) It is shown that for a large number of similar systems the contact (X + , Y + ) process (or (X + , Y + ) reaction) from the ground bound state of the three-body system X + Y + Z - proceeds through the three-particle collision.