Constraints from isoscaling on the source size in energetic heavy ion collisions

In the framework of the statistical multifragmentation model, the nuclear isoscaling analysis is extended to constrain the ratio between the sizes of the decaying sources formed in a collision between two heavy ions. It is found that the ratio between the probabilities of observing n fragments in each event, for each of the sources, follows a scaling law, similar to the traditional nuclear isoscaling. However, the corresponding slope is sensitive to the source sizes. This property is explained analytically using the grand-canonical ensemble. The extent to which our findings are affected by finite size effects and by the deexcitation of the hot primary fragments is investigated. The scaling turns out to be robust and weakly affected by effects implied by these two aspects. We also find that the Poisson distribution is a fairly good approximation to the above mentioned probabilities, associated with both the primordial fragments, produced at the breakup stage, and the final ones, found at the end of the fragment deexcitation process.

Automated summary

In the statistical multifragmentation model, nuclear isoscaling analysis is extended to constrain the ratio between the sizes of decaying sources formed in collisions between heavy ions. The probabilities of observing n fragments in each event for each source follow a scaling law, with the slope sensitive to source sizes. Finite size effects and deexcitation of hot primary fragments have minimal impact on the observed scaling behavior, with the Poisson distribution providing a good approximation to the probabilities of observing fragments.