{ "id": "0709.2490", "version": "v2", "published": "2007-09-16T13:10:28.000Z", "updated": "2009-12-14T00:01:41.000Z", "title": "Semiclassical limit of the scattering cross section as a distribution", "authors": [ "E. Lakshtanov" ], "categories": [ "math-ph", "math.MP" ], "abstract": "We consider quantum scattering from a compactly supported potential $q$. The semiclassical limit amounts to letting the wavenumber $k \\to \\infty$ while rescaling the potential as $k^2 q$ (alternatively, one can scale Planck's constant $\\hbar \\searrow 0$). It is well-known that, under appropriate conditions, for $\\om \\in \\bbS_{n-1}$ such that there is exactly one outgoing ray with direction $\\om$ (in the sense of geometric optics), the differential scattering cross section $|f(\\om,k)|^{2}$ tends to the classical differential cross section $|f_{cl}(\\om)|^2$ as $k \\uparrow \\infty$. It is also clear that the same can not be true if there is more than one outgoing ray with direction $\\om$ or for \\emph{nonregular} directions (including the forward direction $\\theta_0$). However, based on physical intuition, one could conjecture $|f|^2 \\to |f_{cl}|^2 + \\sigma_{cl} \\delta_{\\theta_0}$ where $|f_{cl}|^2$ is the classical cross section and $\\delta_{\\theta_0}$ is the Dirac measure supported at the forward direction $\\theta_0$. The aim of this paper is to prove this conjecture.", "revisions": [ { "version": "v2", "updated": "2009-12-14T00:01:41.000Z" } ], "analyses": { "keywords": [ "semiclassical limit", "distribution", "scale plancks constant", "classical differential cross section", "differential scattering cross section" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2007arXiv0709.2490L" } } }