Applicability of Modified Effective-Range Theory to positron-atom and positron-molecule scattering
نویسندگان
چکیده
We analyze low-energy scattering of positrons on Ar atoms and N2 molecules using Modified Effective-Range Theory (MERT) developped by O’Malley, Spruch and Rosenberg [Journal of Math. Phys. 2, 491 (1961)]. We use formulation of MERT based on exact solutions of Schrödinger equation with polarization potential rather than low-energy expansions of phase shifts into momentum series. We show that MERT describes well experimental data, provided that effective-range expansion is performed both for sand p-wave scattering, which dominate in the considered regime of positron energies (0.4 2 eV). We estimate the values of the s-wave scattering lenght and the effective range for e-Ar and e-N2 collisions.
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