Effects of in-medium cross sections and optical potential on thermal-source formation in p+Au197 reactions at 6.2–14.6GeV∕c
Year: 2004
Type: article
Abstract: 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 $p+^{197}\mathrm{Au}$ reaction at $6.2--14.6\phantom{\rule{0.3em}{0ex}}\mathrm{GeV}∕c$. 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 $25\phantom{\rule{0.3em}{0ex}}\mathrm{fm}∕c$ 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 $d∕p$ and $t∕p$ yield ratios and on the residue mass and charge numbers, is obtained at the time of about $65\phantom{\rule{0.3em}{0ex}}\mathrm{fm}∕c$ from the start of a reaction, for simulations employing reduced in-medium cross sections and momentum-dependent optical potentials. By that time, the preequilibrium nucleon and cluster emission, as well as mean field readjustments, drive the system to a state of depleted average density, $\ensuremath{\rho}∕{\ensuremath{\rho}}_{0}\ensuremath{\sim}1∕4--1∕3$ for central collisions, and low-to-moderate excitation, i.e., the region of nuclear liquid-gas phase transition.
Source: Physical Review C
Authors: S. Turbide, L. Beaulieu, P. Danielewicz, V. E. Viola, R. Roy, K. Kwiatkowski, W.-C. Hsi, G. Wang, T. Lefort, D. S. Bracken, H. Breuer, E. Cornell, F. Gimeno-Nogues, D. S. Ginger, S. Gushue, R. Huang, R. Korteling, W. G. Lynch, K. B. Morley, E. Ramakrishnan, L. P. Remsberg, D. Rowland, M. B. Tsang, H. Xi, S. J. Yennello
Institutions: Université Laval, McGill University, National Superconducting Cyclotron Laboratory, Michigan State University, Indiana University Bloomington, Indiana University, University of Maryland, College Park, Texas A&M University, Brookhaven National Laboratory, Simon Fraser University, Los Alamos National Laboratory
Language: Latvian
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2008547793