Adhikari, S. K.Gibson, W. G.2014-05-202014-05-201992-10-01Physical Review A. College Pk: American Physical Soc, v. 46, n. 7, p. 3967-3977, 1992.1050-2947http://hdl.handle.net/11449/34421A 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 ph cal interest.3967-3977engArtigo10.1103/PhysRevA.46.3967WOS:A1992JV10900053Acesso abertoWOSA1992JV10900053.pdf8031087349809439