A particle is scattered by a potential at sufficiently low energy so that the phase shifts & =() for 1>1. Assume rotational symmetry. (a) Show that the differential scattering cross section has the form (0, $) = A + B cos 0+C cos 0. and determine A, B, and C in terms of phase shifts. (b) Determine the total cross section in terms of A, B, and C. (c) Assume that the differential cross section is known for 0=90 (o=a); 0=180 (o=B2), and 0=45 (o = y). Determine (0, 4) for 0 = 0 in terms of a, , and y. (d) Obtain the imaginary part of the forward scattering amp- litude in terms of a, , and y.