A well known description of superradiance from pointlike collections of many
atoms involves the dissipative motion of a large spin. The pertinent
``superradiance master equation'' allows for a formally exact solution which we
subject to a semiclassical evaluation. The clue is a saddle-point approximation
for an inverse Laplace transform. All previous approximate treatments,
disparate as they may appear, are encompassed in our systematic formulation. A
byproduct is a hitherto unknown rigorous relation between coherences and
probabilities. Our results allow for generalizations to spin dynamics with
chaos in the classical limit.Comment: 12 pages standard revtex; to be published in EPJ
