Isospin observables from fragment energy spectra

TL;DR

This study measures energy spectra of light charged particles and fragments from Sn+Sn collisions at 50 MeV/nucleon, analyzing isospin-sensitive observables to understand nuclear symmetry energy effects.

Contribution

It provides detailed energy spectra and isospin observables from heavy-ion collisions, highlighting the impact of sequential decays on asymmetry measurements.

Findings

Isospin observables show sensitivity to collision dynamics.

Sequential decays significantly affect fragment asymmetry measurements.

Energy spectra enable analysis of isospin ratios as functions of kinetic energy.

Abstract

The energy spectra of light charged particles and intermediate mass fragments from 112Sn+112Sn and 124Sn+124Sn collisions at an incident energy of E/A=50 MeV have been measured with a large array of Silicon strip detectors. We used charged particle multiplicities detected in an array with nearly 4-pi coverage to select data from the central collision events. We study isospin observables analogous to ratios of neutron and proton spectra, including double ratios and yield ratios of t/3He and of asymmetries constructed from fragments with Z=3 to Z=8. Using the energy spectra, we can construct these observables as functions of kinetic energy. Most of the fragment asymmetry observables have a large sensitivity to sequential decays.