14927510
A Transport Model for Nuclear Reactions Induced by Radioactive Beams
Major ingredients of an isospin and momentum dependent transport model for nuclear reactions induced by radioactive beams are outlined. Within the IBUU04 version of this model we study several experimental probes of the equation of state of neutron‐rich matter, especially the density dependence of the nuclear symmetry energy. Comparing with the recent experimental data from NSCL/MSU on isospin diffusion, we found a nuclear symmetry energy of Esym(ρ) ≈ 31.6(ρ/ρ0)1.05 at subnormal densities. Predictions on several observables sensitive to the density dependence of the symmetry energy at supranormal densities accessible at GSI and the planned Rare Isotope Accelerator (RIA) are also made.
14530230
Temperature determination from the lattice gas model.
Determination of temperature from experimental data has become important in searches for critical phenomena in heavy-ion collisions. Widely used methods are ratios of isotopes (which rely on chemical and thermal equilibrium), population ratios of excited states, etc. Using the lattice gas model we propose a new observable: {ital n}{sub ch}/{ital Z} where {ital n}{sub ch} is the charge multiplicity and {ital Z} is the charge of the fragmenting system. We show that the reduced multiplicity is a good measure of the average temperature of the fragmenting system. {copyright} {ital 1996 The American Physical Society.}
119186084
Bimodality and Coulomb effects with a canonical thermodynamic model
Abstract The effect of the Coulomb interaction on the phase diagram of finite nuclei is studied within the Canonical Thermodynamic Model. If Coulomb effects are artificially switched off, this model shows a phenomenology consistent with the liquid–gas phase transition. The inclusion of Coulomb does not significantly affect the phase diagram but it drastically modifies the nature and order parameter of the transition. A clear understanding of the phenomenon can be achieved looking at the distribution of the largest fragment produced in each fragmentation event. Possible connections with experimental observations are outlined.
121860723
Possibility of structure in projectile fragmentation in high energy heavy ion reactions
Abstract We show that a quantum mechanical analogue of the Goldhaber model predicts a structure in the momentum distribution of α's fragmenting from the projectile 6 Li. This structure should be measurable.
15293327
Liquid-Gas Phase Transition in Nuclear Multifragmentation
Heavy-ion collisions allow one to pump energy into a nuclear system. In central collisions of equal size nuclei one can also create a significant amount of compression using high energy nuclear beams. The possibility of studying nuclei far from normal conditions raises the question: can we study phase transitions in nuclei similar, for instance, to the way, one can study phase transition in water? This is the subject of the present article.
2820708
Transverse momenta, nuclear equation of state, and momentum-dependent interactions in heavy-ion collisions.
We investigate the generation of transverse momentum in high-energy heavy-ion collisions and its relation to the nuclear equation of state. We find that streamer chamber data can be fitted by Boltzmann-Uehling-Uhlenbeck calculations with a momentum-dependent potential that closely models realistic nuclear matter interactions and yields an equation of state with {ital K}=215 MeV.
119081223
The Wroblewski parameter from lattice QCD
Enhancement of strangeness production has for long been proposed as a promising signal of quark-gluon plasma production. A convenient indicator for it is the Wroblewski parameter which has been shown to be about a factor of 2 higher in heavy-ion collisions. Using a method proposed by us earlier, we obtained lattice QCD results for the Wroblewski parameter from our simulations of QCD with two light quarks both below and above the chiral transition. Our first principles based and parameter-free result compares well with the A-A data.
119853101
Jet production from nuclei and the cumulative region in nuclear structure functions
Abstract We show that recent data on nuclear dependence of large- E T jet production in proton-nucleus collisions can be accounted for by the nuclear dependence of structure functions, in the framework of lowest order perturbative QCD. A crucial role seems to be played by the extension of nuclear structure functions in the region x > 1 (cumulative region). Such an extension is expected in some models of nuclear effects.
118069164
SYMMETRY-BREAKING MECHANISM IN STRONG INTERACTIONS.
121323084
Microscopic nucleon optical model potential at low energies
Nuclear optical model potentials at low energies have been computed utilizing the two (Micro I and Micro II) versions of the microscopic optical model of Jeukenne et al. A comparison has been made of the experimental nucleon-nucleus interaction data for E<10 MeV with the theoretical predictions obtained using the microscopic optical model.
119408212
Lattice QCD results on strangeness and quasi-quarks in heavy-ion collisions
Fluctuations of conserved quantities in heavy-ion collisions have been proposed as diagnostic tools for the nature of the produced phase. These can be related to the predictions of quark number susceptibilities (QNS) from lattice QCD. Using the diagonal QNS, we extracted the Wroblewski parameter in a dynamical QCD computation. Our results on the cross-correlations χBQ, χBY, χBS and χQY allow us to explore the charge and baryon number of objects that carry flavour. We present evidence that in the high-temperature phase of QCD the different flavour quantum numbers are excited in linkages which are exactly the same as one expects from quarks.