Imaging Sources with Fast and Slow Emission Components

We investigate two-proton correlation functions for reactions in which fast dynamical and slow evaporative proton emission are both present. In such cases, the width of the correlation peak provides the most reliable information about the source size of the fast dynamical component. The maximum of the correlation function is sensitive to the relative yields from the slow and fast emission components. Numerically inverting the correlation function allows one to accurately disentangle fast dynamical from slow evaporative emission and extract details of the shape of the two-proton source.Comment: 13 pages, 4 figure

Non-Thermal Behavior in Multifragment Decay

This research was sponsored by the National Science Foundation Grant NSF PHY-931478

Probing Transport Theories via Two-Proton Source Imaging

Imaging technique is applied to two-proton correlation functions to extract quantitative information about the space-time properties of the emitting source and about the fraction of protons that can be attributed to fast emission mechanisms. These new analysis techniques resolve important ambiguities that bedeviled prior comparisons between measured correlation functions and those calculated by transport theory. Quantitative comparisons to transport theory are presented here. The results of the present analysis differ from those reported previously for the same reaction systems. The shape of the two-proton emitting sources are strongly sensitive to the details about the in-medium nucleon-nucleon cross sections and their density dependence.Comment: 23 pages, 11 figures. Figures are in GIF format. If you need postscript format, please contact: [email protected]

Assessing the Evolutionary Nature of Multifragment Decay

This research was sponsored by the National Science Foundation Grant NSF PHY-931478

Statistical Multifragmentation in Central Au+Au Collisions at 35 MeV/u

Multifragment disintegrations, measured for central Au + Au collisions at E/A = 35 MeV, are analyzed with the Statistical Multifragmentation Model. Charge distributions, mean fragment energies, and two-fragment correlation functions are well reproduced by the statistical breakup of a large, diluted and thermalized system slightly above the multifragmentation threshold.Comment: Latex file, 8 pages + 4 postscript figures available upon request from [email protected]

Multifragment production in Au+Au at 35 MeV/u

Multifragment disintegration has been measured with a high efficiency detection system for the reaction $Au + Au$ at $E/A = 35\ MeV$. From the event shape analysis and the comparison with the predictions of a many-body trajectories calculation the data, for central collisions, are compatible with a fast emission from a unique fragment source.Comment: 9 pages, LaTex file, 4 postscript figures available upon request from [email protected]. - to appear in Phys. Lett.

Thermal source parameters in Au+Au central collisions at 35 A MeV

31Central Au+Au collisions at 35 A MeV are analyzed to find the characteristics of a thermal source, in the framework of the statistical multifragmentation model SMM. A recently introduced backtracing protocol provides an effective comparison of theory and experiment. For the first time the distributions of the central source parameters (density, mass number, excitation energy) are found. The collective energy of primary fragments is also deduced. It is shown that the backtracing procedure allows an estimation of the pre-equilibrium emission. (C) 1998 Published by Elsevier Science B.V.nonenoneP. Désesquelles;M. D'Agostino;A.S. Botvina;M. Bruno;N. Colonna;A. Ferrero;M.L. Fiandri;E. Fuschini;F. Gramegna;I. Iori;G.V. Margagliotti;P.F. Mastinu;P.M. Milazzo;A. Moroni;F. Petruzzelli;R. Rui;G. Vannini;J.D. Dinius;C.K. Gelbke;T. Glasmacher;D.O. Handzy;W.C. Hsi;M. Huang;M.A. Lisa;W.G. Lynch;C.P. Montoya;G.F. Peaslee;L. Phair;C. Schwarz;M.B. Tsang;C. WilliamsP., Désesquelles; M., D'Agostino; A. S., Botvina; M., Bruno; N., Colonna; A., Ferrero; M. L., Fiandri; E., Fuschini; F., Gramegna; I., Iori; Margagliotti, Giacomo; P. F., Mastinu; P. M., Milazzo; A., Moroni; F., Petruzzelli; Rui, Rinaldo; Vannini, Gianni; J. D., Dinius; C. K., Gelbke; T., Glasmacher; D. O., Handzy; W. C., Hsi; M., Huang; M. A., Lisa; W. G., Lynch; C. P., Montoya; G. F., Peaslee; L., Phair; C., Schwarz; M. B., Tsang; C., William