Browsing by Author "Chang, SS"

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    ANALYTICITY OF CHARGE-MONOPOLE SCATTERING-AMPLITUDE
    (American Physical Society, 1978-02-15) Balachandran, AP; Borchardt, S; Chang, SS; Stern, A; Cahalan, R; Ramachandran, R; Rupertsberger, H; Indian Institute of Science (IISC) - Bangalore; Western Kentucky University; Indian Institute of Technology System (IIT System); Indian Institute of Technology (IIT) - Kanpur; University of Vienna; University of Alabama Tuscaloosa
    We study the analyticity in cost of the exact quantum-mechanical electric-charge-magnetic-monopole scattering amplitude by ascribing meaning to its formally divergent partial-wave expansion as the boundary value of an analytic function. This permits us to find an integral representation for the amplitude which displays its analytic structure. On the physical sheet we find only a branch-point singularity in the forward direction, while on each of the infinitely many unphysical sheets we find a logarithmic branch-point singularity in the backward direction as well as the same forward structure. © 1978 The American Physical Society.
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    ROTATIONALLY INVARIANT APPROXIMATION TO CHARGE-MONOPOLE SCATTERING
    (American Physical Society, 1978-02-15) Balachandran, AP; Borchardt, S; Chang, SS; Stern, A; Cahalan, R; Ramachandran, R; Rupertsberger, H; Western Kentucky University; Indian Institute of Technology System (IIT System); Indian Institute of Technology (IIT) - Kanpur; University of Vienna; University of Alabama Tuscaloosa
    A semiclassical approximation derived directly from the Feynman path integral is employed in the study of electric-charge-magnetic-monopole scattering. We show that this approximation, unlike perturbation theory, is consistent with rotational invariance. The semiclassical cross section is explicitly evaluated. It differs from the classical differential cross section for sufficiently large scattering angles due to the interference between the several classical trajectories contributing to the scattering at such angles. It is found that when the scattering angle is not too near the backward direction the semiclassical cross section approaches the classical limit rather slowly as the Dirac quantization number becomes large, or equally as 0 with the product of electric and magnetic charges held fixed. © 1978 The American Physical Society.