DYNAMICAL ATTRACTION OF NONINTERACTING PARTICLES IN QUANTUM-MECHANICAL SYSTEMS - MUONIC DEUTERIUM ATOM

A system of three particles (denoted by 1, 2, and 3) two of which (2 a nd 3) do not interact with each other directly is considered. It if sh own that, in such systems, there arises dynamical attraction between p articles 2 and 3 that is due to the recoiling of particle I coupling t he other two particles and which additionally stabilizes the system. A s a result, the energy of the ground state of the system is lower than the sum of the ground-state energies of the two-particle systems (1, 2) and (1, 3). A variational calculation for the muonic deuterium atom (p(+), n(0), mu(-)) exemplifying systems or the above type demonstrat es that dynamical attraction between the muon and the neutron, which d o not interact with each other directly increases the binding energy o f the (p(+), n(0), mu(-)) system by 4.94 au. There is a similar effect in multiparticle systems. To take this effect into account, trial wav e functions used in variational calculations must involve factors corr esponding to dynamical attraction between particles that do not intera ct with each other directly.