We show that ratios of light-particle energy spectra display scaling properties that can be accu- rately described by effective local chemical potentials. This demonstrates the equivalence of t/3He and n/p spectral ratios and provides an essential test of theoretical predictions of isotopically resolved light-particle spectra. In addition, this approach allows direct comparisons of many theoretical n/p spectral ratios to experiments where charged-particle spectra but not neutron spectra are accurately measured. Such experiments may provide much more quantitative constraints on the density and momentum dependence of the symmetry energy.
Experimental kinetic energy distributions and small-angle two-particle correlation functions involving deuterons and tritons are compared for 36Ar+ 112,124Sn collisions at E/A = 61 MeV (i.e. for systems similar in size, but with different isospin content). A larger triton yield is observed from the more neutron-rich system, as predicted by IBUU simulations, while the emission times of the light clusters are found to be the same for the two Sn-target systems. For both systems, the time sequence tau_{d} < tau_{p} < tau_{t}, is deduced for charged particles emitted from the intermediate velocity source.
Correlations and clustering are of great importance in the study of the Nuclear Equation of State. Information on these items/aspects can be obtained using Heavy-Ion reactions which are described by dynamical theories. We propose a dataset that will be useful for improving the description of light cluster production in transport model approaches. The dataset combines published and new data and is presented in a form that allows direct comparison of the experiment with theoretical predictions. The dataset is ranging in bombarding energy from 32 to 1930 A MeV. In constructing this dataset we put in evidence the existence of a change in the light cluster production mechanism that corresponds to a peak in deuteron production.
The centrality dependence of the midrapidity charged-particle multiplicity density ($|eta|$$<$1) is presented for Au+Au and Cu+Cu collisions at RHIC over a broad range of collision energies. The multiplicity measured in the Cu+Cu system is found to be similar to that measured in the Au+Au system, for an equivalent N$_{rm part}$, with the observed factorization in energy and centrality still persistent in the smaller Cu+Cu system. The extent of the similarities observed for bulk particle production is tested by a comparative analysis of the inclusive transverse momentum distributions for Au+Au and Cu+Cu collisions near midrapidity. It is found that, within the uncertainties of the data, the ratio of yields between the various energies for both Au+Au and Cu+Cu systems are similar and constant with centrality, both in the bulk yields as well as a function of p$_{rm T}$, up to at least 4 GeV/$c$. The effects of multiple nucleon collisions that strongly increase with centrality and energy appear to only play a minor role in bulk and intermediate transverse momentum particle production.
The pion production reaction $pi^+ to pi^+pi^{pm}$ on $^{45}Sc$ was studied at incident pion energies of $T_{pi^{+}}$ = 240, 260, 280, 300, and 320 MeV. The experiment was performed using the $M11$ pion-channel at TRIUMF, and multiparticle events, ($pi^+,pi^+pi^{pm}$) and ($pi^+,pi^+pi^{pm}p$), were detected with the CHAOS spectrometer. Results are reported in the form of both differential and total cross sections, and are compared to theoretical predictions and the reaction phase space. The present investigation of the T-dependence of the $pi^+ A to pi^+pi^{pm} A$ reaction complements earlier examinations of the A-dependence of the reaction, which was measured using $^{2}H$, $^{4}He$, $^{12}C$, $^{16}O$, $^{40}Ca$, and $^{208}Pb$ targets at $sim$280 MeV. Some general properties of the pion-induced pion production reaction in nuclear matter will be presented, based on the combined results of the two studies.
Double-differential cross sections for light-ion (p, d, t, 3He and alpha) production in carbon induced by 96 MeV neutrons have been measured at eight laboratory angles from 20 degrees to 160 degrees in steps of 20 degrees. Experimental techniques are presented as well as procedures for data taking and data reduction. Deduced energy-differential, angle-differential and production cross sections are reported. Experimental cross sections are compared with theoretical reaction model calculations and experimental data in the literature. The measured particle data show marked discrepancies from the results of the model calculations in spectral shape and magnitude. The measured production cross sections for protons, deuterons, tritons, 3He, and alpha particles support the trends suggested by data at lower energies.