E. Cornell

Signals for a transition from surface to bulk emission in thermal multifragmentation.

Excitation-energy-gated two-fragment correlation functions have been studied between E(*)/A = (2-9)A MeV for equilibriumlike sources formed in 8-10 GeV/c pi(-) and p+197Au reactions. Comparison with an N-body Coulomb-trajectory code shows an order of magnitude decrease in the fragment emission time in the interval E(*)/A = (2-5)A MeV, followed by a nearly constant breakup time at higher excitation energy. The decrease in emission time is strongly correlated with the onset of multifragmentation and thermally induced radial expansion, consistent with a transition from surface-dominated to bulk emission expected for spinodal decomposition.

Thermal excitation of heavy nuclei with 5–15 GeV/c antiproton, proton and pion beams

Abstract Excitation-energy distributions have been derived from measurements of 5.0–14.6 GeV/c antiproton, proton and pion reactions with 197 Au target nuclei, using the ISiS 4 π detector array. The maximum probability for producing high excitation-energy events is found for the 8 GeV/c antiproton beam relative to other hadrons, 3 He and p beams from LEAR. For protons and pions, the excitation-energy distributions are nearly independent of hadron type and beam momentum above about 8 GeV/c. The excitation energy enhancement for p beams and the saturation effect are qualitatively consistent with intranuclear cascade code predictions. For all systems studied, maximum cluster sizes are observed for residues with E ∗ /A∼6 MeV.

Fragment emission from modestly excited nuclear systems

Abstract Fragment emission patterns occurring in nuclear systems of modest excitation are studied. Exclusive measurement of fragment emission in 14 N+ 197 Au reactions at E A = 100, 130 and 156 MeV allows selection of central collisions where a single source dominates the decay. Low threshold measurement of IMF emission for these events allows investigation of the influence of detector threshold effects. The time scale of fragment emission is deduced using fragment-fragment velocity correlations. Comparisons are made to the predictions of a statistical decay model.

Effects of in-medium cross sections and optical potential on thermal-source formation in p+{sup 197}Au reactions at 6.2-14.6 GeV/c

Effects of in-medium cross sections and of optical potential on preequilibrium emission and on formation of a thermal source are investigated by comparing the results of transport simulations with experimental results from the

Probing the nuclear EOS with GeV light-ion beams

p+^{197}\mathrm{Au}

Exclusive studies of 130-270 MeV {sup 3}He- and 200-MeV proton-induced reactions on {sup 27}Al, {sup nat}Ag, and {sup 197}Au

reaction at

Multifragmentation with GeV light-ion beams

6.2\char21{}14.6\phantom{\rule{0.3em}{0ex}}\mathrm{GeV}∕c

Assessing the Evolutionary Nature of Multifragment Decay

. The employed transport model includes light-composite-particle production and allows for inclusion of in-medium particle-particle cross-section reduction and of momentum dependence in the particle optical potentials. Compared to the past, the model incorporates improved parametrizations of elementary high-energy processes. The simulations indicate that the majority of energy deposition occurs during the first

Exclusive studies of angular distributions in GeV hadron-induced reactions with {sup 197}Au

25\phantom{\rule{0.3em}{0ex}}\mathrm{fm}∕c

Investigating the Evolution of Multifragmenting Systems with Fragment Emission Order

of a reaction. This is followed by a preequilibrium emission and readjustment of system density and momentum distribution toward an equilibrated system. Within different variants of calculations, the best agreement with data, on the