Influence of the Coulomb Interaction on the Chemical Equilibrium of Nuclear Systems at Break-Up

The importance of a Coulomb correction to the formalism proposed by Albergo et al. for determining the temperatures of nuclear systems at breakup and the densities of free nucleon gases is discussed. While the proposed correction has no effect on the temperatures extracted based on double isotope ratios, it becomes non-negligible when such temperatures or densities of free nucleon gases are extracted based on multiplicities of heavier fragments of different atomic numbers. PACS numbers: 25.70.Mn, 25.70.Pq, 25.70.-z, 24.10.Pa The formalism by Albergo, Costa, Costanzo, and Rubbino (ACCR) [1] offers simple and elegant prescriptions for the experimental determination of the temperature T , and of the free nucleon densities, ρnF and ρpF in a nuclear system at the instance of the break-up. This formalism presumes a specific scenario for the decay of excited systems, similar to the scenarios modeled by the Berlin Microcanonical Metropolis Monte Carlo [2] and the Copenhagen Statistical Multifragmentation [3] models. Therefore, it may be expected to be meaningful in circumstances (in an excitation energy domain), where the use of the above two more complete models can be justified. On the other hand, the ACCR formalism is incompatible with models such as the equilibrium-statistical model GEMINI [4] and the