Measurement of Complex Fragments and Clues to the Entropy Production from 42-137-MeV/nucleon Ar + Au

Abstract

Intermediate-rapidity fragments with $A=1\ensuremath{-}14$ emitted from 42-137-MeV/nucleon Ar + Au have been measured. Evidence is presented that these fragments arise from a common moving source. Entropy values are extracted from the mass distributions by use of quantum statistical and Hauser-Feshbach theories. The extracted entropy values of $\frac{S}{A}\ensuremath{\approx}2\ensuremath{-}2.4$ are much smaller than the values expected from measured deuteron-to-proton ratios, but are still considerably higher than theoretically predicted values.