Adhikari, Sadhan K. [UNESP]Gibson, William G.2022-04-282022-04-281992-01-01Physical Review A, v. 46, n. 7, p. 3967-3977, 1992.1050-2947http://hdl.handle.net/11449/225130A study of the analytic behavior of different few-particle scattering amplitudes at low energies in two space dimensions is presented. Such a study is of use in modeling and understanding different few-particle processes at low energies. A detailed discussion of the energy and the momentum dependence of the partial-wave on-the-energy-shell and off-the-energy-shell two-particle t matrices is given. These t-matrix elements tend to zero as the energy and momentum variables tend to zero. The multiple-scattering series is used to show that the connected three-to-three amplitudes diverge in the low-energy-momentum limit. Unitarity relations are used to show that the connected two-to-three and one-to-three amplitudes have specific logarithmic singularities at the m-particle breakup threshold. The subenergy singularity in the two-to-three amplitudes is also studied, and comments are made on some applications of the present study in different problems of physical interest. © 1992 The American Physical Society.3967-3977engArtigo10.1103/PhysRevA.46.39672-s2.0-4243557845