Proton-Proton Correlation Functions Measured Using Position-Sensitive FAUST

The nuclear Equation of State (nEoS) is important to a more fundamental understanding of nuclear matter, particularly in asymmetric systems such as neutron stars. Proton-proton (pp) correlation functions have been predicted to be sensitive to the density-dependence of the asymmetry energy in the nEoS in simulations using transport models. In order to examine this relationship, the Forward Array Using Silicon Technology (FAUST) has been commissioned with position-sensitive silicon detectors as the ∆E detectors to increase resolution in momentum space. The upgraded FAUST was used to measure charged particles produced in reactions of ^40Ar+ ^58Fe and ^40Ca+ ^58Ni at 40 MeV/u and ^40Ar+ ^70Zn and ^40Ar+ ^58Fe at 30 MeV/u. These systems were chosen in order to vary the neutron-proton asymmetry between systems of similar size. Light charged particle correlation functions and proton-proton correlation functions were extracted for all four of these systems. Correlation functions extracted from simulations using a Boltzmann-Uehling-Uhlenbeck transport model show no difference between soft and stiff parametrizations of the asymmetry energy. Comparisons of the strength of experimental proton-proton correlation functions amongst the same beam energy and the same system with varying system composition or energy provide another experimental observable for future comparison with simulation results

Using Light Charged Particles to Probe the Asymmetry Dependence of the Nuclear Caloric Curve

Recently, we observed a clear dependence of the nuclear caloric curve on neutron-proton asymmetry $\frac{N-Z}{A}$ through examination of fully reconstructed equilibrated quasi-projectile sources produced in heavy ion collisions at E/A = 35 MeV. In the present work, we extend our analysis using multiple light charged particle probes of the temperature. Temperatures are extracted with five distinct probes using a kinetic thermometer approach. Additionally, temperatures are extracted using two probes within a chemical thermometer approach (Albergo method). All seven measurements show a significant linear dependence of the source temperature on the source asymmetry. For the kinetic thermometer, the strength of the asymmetry dependence varies with the probe particle species in a way which is consistent with an average emission-time ordering.Comment: 7 pages, 4 figure

Proton-Proton Correlation Functions Measured Using Position-Sensitive FAUST

The nuclear Equation of State (nEoS) is important to a more fundamental understanding of nuclear matter, particularly in asymmetric systems such as neutron stars. Proton-proton (pp) correlation functions have been predicted to be sensitive to the density-dependence of the asymmetry energy in the nEoS in simulations using transport models. In order to examine this relationship, the Forward Array Using Silicon Technology (FAUST) has been commissioned with position-sensitive silicon detectors as the ∆E detectors to increase resolution in momentum space. The upgraded FAUST was used to measure charged particles produced in reactions of ^40Ar+ ^58Fe and ^40Ca+ ^58Ni at 40 MeV/u and ^40Ar+ ^70Zn and ^40Ar+ ^58Fe at 30 MeV/u. These systems were chosen in order to vary the neutron-proton asymmetry between systems of similar size. Light charged particle correlation functions and proton-proton correlation functions were extracted for all four of these systems. Correlation functions extracted from simulations using a Boltzmann-Uehling-Uhlenbeck transport model show no difference between soft and stiff parametrizations of the asymmetry energy. Comparisons of the strength of experimental proton-proton correlation functions amongst the same beam energy and the same system with varying system composition or energy provide another experimental observable for future comparison with simulation results

Constraints on the asymmetric equation of state from heavy-ion collisions

Nuclear matter is one of the most fascinating materials that exists.Therefore elucidating the equation-of-state of nuclear matter is a fundamentally interesting question. Additionally, the nuclear equationof-state has impacts on astrophysical observables. One important means of constraining the nuclear equation-of-state is through studying heavy-ion collisions. Nuclear material has two components - neutrons and protons - the ratio of which impacts the equation-of-state. Measurements of fragments emitted from reactions of nuclei with different ratios of neutrons and protons - and comparison to simulations based on various underlying interactions - have placed constraints on both the symmetric and asymmetric parts of the equation of state

Constraints on the asymmetric equation of state from heavy-ion collisions

Nuclear matter is one of the most fascinating materials that exists.Therefore elucidating the equation-of-state of nuclear matter is a fundamentally interesting question. Additionally, the nuclear equationof-state has impacts on astrophysical observables. One important means of constraining the nuclear equation-of-state is through studying heavy-ion collisions. Nuclear material has two components - neutrons and protons - the ratio of which impacts the equation-of-state. Measurements of fragments emitted from reactions of nuclei with different ratios of neutrons and protons - and comparison to simulations based on various underlying interactions - have placed constraints on both the symmetric and asymmetric parts of the equation of state