On the three-body kinematics, we investigate the threshold behavior which appears not only at the three-body break-up threshold (3BT), but also at the quasi two-body threshold (Q2T) for the reactions:
A+(BC)→A+B+C , and
(ABC)→A+(BC) , respectively. Recently, the author proposed a general particle
transfer (GPT) potential which appears, not only at the 3BT, but also at the Q2T between A and (BC). The new potential indicates a Yukawa-type potential for short range, but a
1/rn -type potential for long range. The long range part of the GPT potential for
n=1 indicates an attractive Coulomb-like or a gravitation-like potential. While,
n=2 indicates the Efimov-like potential between A and (BC). The three-body binding energy:
En=ϵ+ζn with the two-body binding energy
ϵ , and the separation energy
ζn for
(ABC)→A+(BC) satisfies
En/En+1=ζn/ζn+1 =const for
ϵ=0 or the two-body scattering length:
a→∞ (i.e. the two-body unitary limit). At the Q2T, the condensation of the three-body binding energy is given by the GPT-potential in the form of
En/En+1=(ζn+ϵ)/(ζn+1+ϵ)→1 (const) for
n→∞ (with
ζn→0 ) which implies the existence of Efimov-like states at the Q2T in the hadron systems, thereby the possibility of “ultra low energy nuclear transformation”, where the three-body binding energies degenerate at zero energy. Finally, the origin of such a long range potential will be clarified.
This work reviews recent advances in the analytical treatment of the continuum spectrum of correlated few-body non-relativistic Coulomb systems. The exactly solvable two-body problem serves as an introduction to the non-separable three-particle system. For the latter case we discuss the existence of an approximate separability of the long and the short-range dynamics which is exposed in an appropriately chosen curvilinear coordinates. The three-body wave functions of the long-ranged part of the Hamiltonian are derived and methods are presented to account approximately for the short-ranged dynamics. Furthermore, we present a generalization of the methods employed for the derivation of the three-body wave functions to the scattering states of
N charged particles. To deal with thermodynamic properties of finite systems we develop and discuss a recent Green function methodology designed for the non-perturbative regime. In addition, we give a brief account on how thermodynamic properties and critical phenomena can be exposed in finite interacting systems.